Polymers with improved toughness and ESCR for large-part blow molding applications

ABSTRACT

Disclosed herein are ethylene-based polymers having a density greater than 0.945 g/cm3, a high load melt index less than 25 g/10 min, a peak molecular weight ranging from 52,000 to 132,000 g/mol, and an environmental stress crack resistance of at least 250 hours. These polymers have the processability of chromium-based resins, but with improved impact strength and stress crack resistance, and can be used in large-part blow molding applications.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 14/995,268, filed on Jan. 14, 2016, now U.S. Pat.No. 9,550,849, which is a continuation application of U.S. patentapplication Ser. No. 14/205,422, filed on Mar. 12, 2014, now U.S. Pat.No. 9,273,170, the disclosures of which are incorporated herein byreference in their entirety.

BACKGROUND OF THE INVENTION

Polyolefins such as high density polyethylene (HDPE) homopolymer andlinear low density polyethylene (LLDPE) copolymer can be produced usingvarious combinations of catalyst systems and polymerization processes.Chromium-based catalyst systems can, for example, produce olefinpolymers having good extrusion processibility and polymer melt strength,typically due to their broad molecular weight distribution (MWD).

In some end-use applications, it can be beneficial to have theprocessibility and melt strength similar to that of an olefin polymerproduced from a chromium-based catalyst system, as well as improvementsin toughness, impact strength, and environmental stress crack resistance(ESCR) at equivalent or higher polymer densities. Accordingly, it is tothese ends that the present invention is directed.

SUMMARY OF THE INVENTION

This summary is provided to introduce a selection of concepts in asimplified form that are further described below in the detaileddescription. This summary is not intended to identify required oressential features of the claimed subject matter. Nor is this summaryintended to be used to limit the scope of the claimed subject matter.

The present invention generally relates to new catalyst compositions,methods for preparing catalyst compositions, methods for using thecatalyst compositions to polymerize olefins, the polymer resins producedusing such catalyst compositions, and articles produced using thesepolymer resins. In particular, aspects of the present invention aredirected to catalyst compositions employing two metallocene catalystcomponents. The first catalyst component can comprise an unbridgedmetallocene compound, for instance, an unbridged zirconium or hafniumbased metallocene compound containing two cyclopentadienyl groups, twoindenyl groups, or a cyclopentadienyl and an indenyl group. The secondcatalyst component can comprise a bridged metallocene compound, forinstance, a bridged zirconium or hafnium based metallocene compound witha cyclopentadienyl group and a fluorenyl group, and with an alkenylsubstituent on the bridging group and/or on the cyclopentadienyl group.Such catalyst compositions can be used to produce, for example,ethylene-based copolymers for variety of end-use applications, such asthe blow molding of large parts.

The present invention also contemplates and encompasses olefinpolymerization processes. Such processes can comprise contacting acatalyst composition with an olefin monomer and optionally an olefincomonomer under polymerization conditions to produce an olefin polymer.Generally, the catalyst composition employed can comprise any of thecatalyst component I (unbridged) metallocene compounds, any of thecatalyst component II (bridged) metallocene compounds, and any of theactivators and optional co-catalysts disclosed herein. For example,organoaluminum compounds can be utilized in the catalyst compositionsand/or polymerization processes.

Polymers produced from the polymerization of olefins, resulting inhomopolymers, copolymers, terpolymers, etc., can be used to producevarious articles of manufacture. A representative and non-limitingexample of an olefin polymer (e.g., an ethylene copolymer) consistentwith aspects of this invention can be characterized as having thefollowing properties: a density of greater than or equal to about 0.945g/cm³, a high load melt index (HLMI) in a range from about 1 to about 25g/10 min, a peak molecular weight (Mp) in a range from about 52,000 toabout 132,000 g/mol, and an environmental stress crack resistance (ESCR)of at least 250 hours. Another representative and non-limitingethylene-based polymer described herein can have a density of greaterthan or equal to about 0.945 g/cm³, a high load melt index (HLMI) in arange from about 1 to about 25 g/10 min, a weight-average molecularweight (Mw) in a range from about 275,000 to about 800,000 g/mol, anumber-average molecular weight (Mn) in a range from about 20,000 toabout 60,000 g/mol, and a ratio of Mw/Mn in a range from about 5 toabout 22. These polymers, in further aspects, can be characterized bylow levels of long chain branches (LCB), and/or a reverse comonomerdistribution, and/or a bimodal molecular weight distribution, and/orhigh impact resistance, and/or excellent blow molding performance andprocessability.

Both the foregoing summary and the following detailed descriptionprovide examples and are explanatory only. Accordingly, the foregoingsummary and the following detailed description should not be consideredto be restrictive. Further, features or variations may be provided inaddition to those set forth herein. For example, certain aspects andembodiments may be directed to various feature combinations andsub-combinations described in the detailed description.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 presents a plot of the molecular weight distributions of thepolymers of Examples 2-5.

FIG. 2 presents a plot of the molecular weight distributions of thepolymers of Examples 1 and 6-8.

FIG. 3 presents a dynamic rheology plot (viscosity versus frequency) at190° C. for the polymers of Examples 1 and 3-5.

FIG. 4 presents a dynamic rheology plot (viscosity versus frequency) at190° C. for the polymers of Examples 1 and 6-8.

FIG. 5 presents a plot of the radius of gyration versus the molecularweight for a linear standard and the polymers of Examples 4, 5, and 7.

DEFINITIONS

To define more clearly the terms used herein, the following definitionsare provided. Unless otherwise indicated, the following definitions areapplicable to this disclosure. If a term is used in this disclosure butis not specifically defined herein, the definition from the IUPACCompendium of Chemical Terminology, 2nd Ed (1997), can be applied, aslong as that definition does not conflict with any other disclosure ordefinition applied herein, or render indefinite or non-enabled any claimto which that definition is applied. To the extent that any definitionor usage provided by any document incorporated herein by referenceconflicts with the definition or usage provided herein, the definitionor usage provided herein controls.

While compositions and methods are described herein in terms of“comprising” various components or steps, the compositions and methodscan also “consist essentially of” or “consist of” the various componentsor steps, unless stated otherwise. For example, a catalyst compositionconsistent with aspects of the present invention can comprise;alternatively, can consist essentially of; or alternatively, can consistof; (i) catalyst component I, (ii) catalyst component II, (iii) anactivator, and (iv) optionally, a co-catalyst.

The terms “a,” “an,” “the,” etc., are intended to include pluralalternatives, e.g., at least one, unless otherwise specified. Forinstance, the disclosure of “an activator-support” or “a metallocenecompound” is meant to encompass one, or mixtures or combinations of morethan one, activator-support or metallocene compound, respectively,unless otherwise specified.

Generally, groups of elements are indicated using the numbering schemeindicated in the version of the periodic table of elements published inChemical and Engineering News, 63(5), 27, 1985. In some instances, agroup of elements can be indicated using a common name assigned to thegroup; for example, alkali metals for Group 1 elements, alkaline earthmetals for Group 2 elements, transition metals for Group 3-12 elements,and halogens or halides for Group 17 elements.

For any particular compound disclosed herein, the general structure orname presented is also intended to encompass all structural isomers,conformational isomers, and stereoisomers that can arise from aparticular set of substituents, unless indicated otherwise. Thus, ageneral reference to a compound includes all structural isomers unlessexplicitly indicated otherwise; e.g., a general reference to pentaneincludes n-pentane, 2-methyl-butane, and 2,2-dimethylpropane, while ageneral reference to a butyl group includes an n-butyl group, asec-butyl group, an iso-butyl group, and a tert-butyl group.Additionally, the reference to a general structure or name encompassesall enantiomers, diastereomers, and other optical isomers whether inenantiomeric or racemic forms, as well as mixtures of stereoisomers, asthe context permits or requires. For any particular formula or name thatis presented, any general formula or name presented also encompasses allconformational isomers, regioisomers, and stereoisomers that can arisefrom a particular set of substituents.

The term “substituted” when used to describe a group, for example, whenreferring to a substituted analog of a particular group, is intended todescribe any non-hydrogen moiety that formally replaces a hydrogen inthat group, and is intended to be non-limiting. A group or groups canalso be referred to herein as “unsubstituted” or by equivalent termssuch as “non-substituted,” which refers to the original group in which anon-hydrogen moiety does not replace a hydrogen within that group.Unless otherwise specified, “substituted” is intended to be non-limitingand include inorganic substituents or organic substituents as understoodby one of ordinary skill in the art.

The term “hydrocarbon” whenever used in this specification and claimsrefers to a compound containing only carbon and hydrogen. Otheridentifiers can be utilized to indicate the presence of particulargroups in the hydrocarbon (e.g., halogenated hydrocarbon indicates thepresence of one or more halogen atoms replacing an equivalent number ofhydrogen atoms in the hydrocarbon). The term “hydrocarbyl group” is usedherein in accordance with the definition specified by IUPAC: a univalentgroup formed by removing a hydrogen atom from a hydrocarbon (that is, agroup containing only carbon and hydrogen). Non-limiting examples ofhydrocarbyl groups include alkyl, alkenyl, aryl, and aralkyl groups,amongst other groups.

The term “polymer” is used herein generically to include olefinhomopolymers, copolymers, terpolymers, and so forth. A copolymer isderived from an olefin monomer and one olefin comonomer, while aterpolymer is derived from an olefin monomer and two olefin comonomers.Accordingly, “polymer” encompasses copolymers, terpolymers, etc.,derived from any olefin monomer and comonomer(s) disclosed herein.Similarly, an ethylene polymer would include ethylene homopolymers,ethylene copolymers, ethylene terpolymers, and the like. As an example,an olefin copolymer, such as an ethylene copolymer, can be derived fromethylene and a comonomer, such as 1-butene, 1-hexene, or 1-octene. Ifthe monomer and comonomer were ethylene and 1-hexene, respectively, theresulting polymer can be categorized an as ethylene/1-hexene copolymer.

In like manner, the scope of the term “polymerization” includeshomopolymerization, copolymerization, terpolymerization, etc. Therefore,a copolymerization process can involve contacting one olefin monomer(e.g., ethylene) and one olefin comonomer (e.g., 1-hexene) to produce acopolymer.

The term “co-catalyst” is used generally herein to refer to compoundssuch as aluminoxane compounds, organoboron or organoborate compounds,ionizing ionic compounds, organoaluminum compounds, organozinccompounds, organomagnesium compounds, organolithium compounds, and thelike, that can constitute one component of a catalyst composition, whenused, for example, in addition to an activator-support. The term“co-catalyst” is used regardless of the actual function of the compoundor any chemical mechanism by which the compound may operate.

The terms “chemically-treated solid oxide,” “treated solid oxidecompound,” and the like, are used herein to indicate a solid, inorganicoxide of relatively high porosity, which can exhibit Lewis acidic orBrønsted acidic behavior, and which has been treated with anelectron-withdrawing component, typically an anion, and which iscalcined. The electron-withdrawing component is typically anelectron-withdrawing anion source compound. Thus, the chemically-treatedsolid oxide can comprise a calcined contact product of at least onesolid oxide with at least one electron-withdrawing anion sourcecompound. Typically, the chemically-treated solid oxide comprises atleast one acidic solid oxide compound. The “activator-support” of thepresent invention can be a chemically-treated solid oxide. The terms“support” and “activator-support” are not used to imply these componentsare inert, and such components should not be construed as an inertcomponent of the catalyst composition. The term “activator,” as usedherein, refers generally to a substance that is capable of converting ametallocene component into a catalyst that can polymerize olefins, orconverting a contact product of a metallocene component and a componentthat provides an activatable ligand (e.g., an alkyl, a hydride) to themetallocene, when the metallocene compound does not already comprisesuch a ligand, into a catalyst that can polymerize olefins. This term isused regardless of the actual activating mechanism. Illustrativeactivators include activator-supports, aluminoxanes, organoboron ororganoborate compounds, ionizing ionic compounds, and the like.Aluminoxanes, organoboron or organoborate compounds, and ionizing ioniccompounds generally are referred to as activators if used in a catalystcomposition in which an activator-support is not present. If thecatalyst composition contains an activator-support, then thealuminoxane, organoboron or organoborate, and ionizing ionic materialsare typically referred to as co-catalysts.

The term “metallocene” as used herein describes compounds comprising atleast one η³ to η⁵-cycloalkadienyl-type moiety, wherein η³ toη⁵-cycloalkadienyl moieties include cyclopentadienyl ligands, indenylligands, fluorenyl ligands, and the like, including partially saturatedor substituted derivatives or analogs of any of these. Possiblesubstituents on these ligands may include H, therefore this inventioncomprises ligands such as tetrahydroindenyl, tetrahydrofluorenyl,octahydrofluorenyl, partially saturated indenyl, partially saturatedfluorenyl, substituted partially saturated indenyl, substitutedpartially saturated fluorenyl, and the like. In some contexts, themetallocene is referred to simply as the “catalyst,” in much the sameway the term “co-catalyst” is used herein to refer to, for example, anorganoaluminum compound.

The terms “catalyst composition,” “catalyst mixture,” “catalyst system,”and the like, do not depend upon the actual product or compositionresulting from the contact or reaction of the initial components of thedisclosed or claimed catalyst composition/mixture/system, the nature ofthe active catalytic site, or the fate of the co-catalyst, themetallocene compound(s), or the activator (e.g., activator-support),after combining these components. Therefore, the terms “catalystcomposition,” “catalyst mixture,” “catalyst system,” and the like,encompass the initial starting components of the composition, as well aswhatever product(s) may result from contacting these initial startingcomponents, and this is inclusive of both heterogeneous and homogenouscatalyst systems or compositions. The terms “catalyst composition,”“catalyst mixture,” “catalyst system,” and the like, can be usedinterchangeably throughout this disclosure.

The term “contact product” is used herein to describe compositionswherein the components are contacted together in any order, in anymanner, and for any length of time. For example, the components can becontacted by blending or mixing. Further, contacting of any componentcan occur in the presence or absence of any other component of thecompositions described herein. Combining additional materials orcomponents can be done by any suitable method. Further, the term“contact product” includes mixtures, blends, solutions, slurries,reaction products, and the like, or combinations thereof. Although“contact product” can include reaction products, it is not required forthe respective components to react with one another. Similarly, the term“contacting” is used herein to refer to materials which can be blended,mixed, slurried, dissolved, reacted, treated, or otherwise contacted insome other manner.

Although any methods, devices, and materials similar or equivalent tothose described herein can be used in the practice or testing of theinvention, the typical methods, devices and materials are hereindescribed.

All publications and patents mentioned herein are incorporated herein byreference for the purpose of describing and disclosing, for example, theconstructs and methodologies that are described in the publications,which might be used in connection with the presently describedinvention. The publications discussed throughout the text are providedsolely for their disclosure prior to the filing date of the presentapplication. Nothing herein is to be construed as an admission that theinventors are not entitled to antedate such disclosure by virtue ofprior invention.

Applicants disclose several types of ranges in the present invention.When Applicants disclose or claim a range of any type, Applicants'intent is to disclose or claim individually each possible number thatsuch a range could reasonably encompass, including end points of therange as well as any sub-ranges and combinations of sub-rangesencompassed therein. For example, when the Applicants disclose or claima chemical moiety having a certain number of carbon atoms, Applicants'intent is to disclose or claim individually every possible number thatsuch a range could encompass, consistent with the disclosure herein. Forexample, the disclosure that a moiety is a C₁ to C₁₈ hydrocarbyl group,or in alternative language, a hydrocarbyl group having from 1 to 18carbon atoms, as used herein, refers to a moiety that can have 1, 2, 3,4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, or 18 carbon atoms, aswell as any range between these two numbers (for example, a C₁ to C₈hydrocarbyl group), and also including any combination of ranges betweenthese two numbers (for example, a C₂ to C₄ and a C₁₂ to C₁₆ hydrocarbylgroup).

Similarly, another representative example follows for the peak molecularweight (Mp) of an olefin polymer produced in an aspect of thisinvention. By a disclosure that the Mp can be in a range from about50,000 to about 130,000 g/mol, Applicants intend to recite that the Mpcan be any molecular weight in the range and, for example, can be equalto about 50,000, about 60,000, about 70,000, about 80,000, about 90,000,about 100,000, about 110,000, about 120,000, or about 130,000 g/mol.Additionally, the Mp can be within any range from about 50,000 to about130,000 (for example, from about 60,000 to about 80,000), and this alsoincludes any combination of ranges between about 50,000 and about130,000 (for example, the Mp can be in a range from about 52,000 toabout 75,000, or from about 90,000 to about 125,000). Likewise, allother ranges disclosed herein should be interpreted in a manner similarto these examples.

Applicants reserve the right to proviso out or exclude any individualmembers of any such group, including any sub-ranges or combinations ofsub-ranges within the group, that can be claimed according to a range orin any similar manner, if for any reason Applicants choose to claim lessthan the full measure of the disclosure, for example, to account for areference that Applicants may be unaware of at the time of the filing ofthe application. Further, Applicants reserve the right to proviso out orexclude any individual substituents, analogs, compounds, ligands,structures, or groups thereof, or any members of a claimed group, if forany reason Applicants choose to claim less than the full measure of thedisclosure, for example, to account for a reference that Applicants maybe unaware of at the time of the filing of the application.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed generally to new catalystcompositions, methods for preparing catalyst compositions, methods forusing the catalyst compositions to polymerize olefins, the polymerresins produced using such catalyst compositions, and articles producedusing these polymer resins. In particular, the present invention relatesto catalyst compositions containing two metallocene components, topolymerization processes utilizing such catalyst compositions, and tothe resulting olefin polymers produced from the polymerizationprocesses.

Catalyst Component I

Catalyst component I can comprise an unbridged zirconium or hafniumbased metallocene compound and/or an unbridged zirconium and/or hafniumbased dinuclear metallocene compound. In one aspect, for instance,catalyst component I can comprise an unbridged zirconium or hafniumbased metallocene compound containing two cyclopentadienyl groups, twoindenyl groups, or a cyclopentadienyl and an indenyl group. In anotheraspect, catalyst component I can comprise an unbridged zirconium orhafnium based metallocene compound containing two cyclopentadienylgroups. In yet another aspect, catalyst component I can comprise anunbridged zirconium or hafnium based metallocene compound containing twoindenyl groups. In still another aspect, catalyst component I cancomprise an unbridged zirconium or hafnium based metallocene compoundcontaining a cyclopentadienyl and an indenyl group.

In some aspects, catalyst component I can comprise an unbridgedzirconium based metallocene compound containing two cyclopentadienylgroups, two indenyl groups, or a cyclopentadienyl and an indenyl group,while in other aspects, catalyst component I can comprise a dinuclearunbridged metallocene compound with an alkenyl linking group.

Catalyst component I can comprise, in particular aspects of thisinvention, an unbridged metallocene compound having formula (I):

Within formula (I), M, Cp^(A), Cp^(B), and each X are independentelements of the unbridged metallocene compound. Accordingly, theunbridged metallocene compound having formula (I) can be described usingany combination of M, Cp^(A), Cp^(B), and X disclosed herein.

Unless otherwise specified, formula (I) above, any other structuralformulas disclosed herein, and any metallocene complex, compound, orspecies disclosed herein are not designed to show stereochemistry orisomeric positioning of the different moieties (e.g., these formulas arenot intended to display cis or trans isomers, or R or Sdiastereoisomers), although such compounds are contemplated andencompassed by these formulas and/or structures.

In accordance with aspects of this invention, the metal in formula (I),M, can be Ti, Zr, or Hf. In one aspect, for instance, M can be Zr or Hf,while in another aspect, M can be Ti; alternatively, M can be Zr; oralternatively, M can be Hf.

Each X in formula (I) independently can be a monoanionic ligand. In someaspects, suitable monoanionic ligands can include, but are not limitedto, H (hydride), BH₄, a halide, a C₁ to C₃₆ hydrocarbyl group, a C₁ toC₃₆ hydrocarboxy group, a C₁ to C₃₆ hydrocarbylaminyl group, a C₁ to C₃₆hydrocarbylsilyl group, a C₁ to C₃₆ hydrocarbylaminylsilyl group, —OBR¹₂, or —OSO₂R¹, wherein R¹ is a C₁ to C₃₆ hydrocarbyl group. It iscontemplated that each X can be either the same or a differentmonoanionic ligand.

In one aspect, each X independently can be H, BH₄, a halide (e.g., F,Cl, Br, etc.), a C₁ to C₁₈ hydrocarbyl group, a C₁ to C₁₈ hydrocarboxygroup, a C₁ to C₁₈ hydrocarbylaminyl group, a C₁ to C₁₈ hydrocarbylsilylgroup, or a C₁ to C₁₈ hydrocarbylaminylsilyl group. Alternatively, eachX independently can be H, BH₄, a halide, OBR¹ ₂, or OSO₂R¹, wherein R¹is a C₁ to C₁₈ hydrocarbyl group. In another aspect, each Xindependently can be H, BH₄, a halide, a C₁ to C₁₂ hydrocarbyl group, aC₁ to C₁₂ hydrocarboxy group, a C₁ to C₁₂ hydrocarbylaminyl group, a C₁to C₁₂ hydrocarbylsilyl group, a C₁ to C₁₂ hydrocarbylaminylsilyl group,OBR¹ ₂, or OSO₂R¹, wherein R¹ is a C₁ to C₁₂ hydrocarbyl group. Inanother aspect, each X independently can be H, BH₄, a halide, a C₁ toC₁₀ hydrocarbyl group, a C₁ to C₁₀ hydrocarboxy group, a C₁ to C₁₀hydrocarbylaminyl group, a C₁ to C₁₀ hydrocarbylsilyl group, a C₁ to C₁₀hydrocarbylaminylsilyl group, OBR¹ ₂, or OSO₂R¹, wherein R¹ is a C₁ toC₁₀ hydrocarbyl group. In yet another aspect, each X independently canbe H, BH₄, a halide, a C₁ to C₈ hydrocarbyl group, a C₁ to C₈hydrocarboxy group, a C₁ to C₈ hydrocarbylaminyl group, a C₁ to C₈hydrocarbylsilyl group, a C₁ to C₈ hydrocarbylaminylsilyl group, OBR¹ ₂,or OSO₂R¹, wherein R¹ is a C₁ to C₈ hydrocarbyl group. In still anotheraspect, each X independently can be a halide or a C₁ to C₁₈ hydrocarbylgroup. For example, each X can be Cl.

The hydrocarbyl group which can be an X in formula (I) can be a C₁ toC₃₆ hydrocarbyl group, including, but not limited to, a C₁ to C₃₆ alkylgroup, a C₂ to C₃₆ alkenyl group, a C₄ to C₃₆ cycloalkyl group, a C₆ toC₃₆ aryl group, or a C₇ to C₃₆ aralkyl group. For instance, each Xindependently can be a C₁ to C₁₈ alkyl group, a C₂ to C₁₈ alkenyl group,a C₄ to C₁₈ cycloalkyl group, a C₆ to C₁₈ aryl group, or a C₇ to C₁₈aralkyl group; alternatively, each X independently can be a C₁ to C₁₂alkyl group, a C₂ to C₁₂ alkenyl group, a C₄ to C₁₂ cycloalkyl group, aC₆ to C₁₂ aryl group, or a C₇ to C₁₂ aralkyl group; alternatively, eachX independently can be a C₁ to C₁₀ alkyl group, a C₂ to C₁₀ alkenylgroup, a C₄ to C₁₀ cycloalkyl group, a C₆ to C₁₀ aryl group, or a C₇ toC₁₀ aralkyl group; or alternatively, each X independently can be a C₁ toC₅ alkyl group, a C₂ to C₅ alkenyl group, a C₅ to C₈ cycloalkyl group, aC₆ to C₈ aryl group, or a C₇ to C₈ aralkyl group.

Accordingly, in some aspects, the alkyl group which can be an X informula (I) can be a methyl group, an ethyl group, a propyl group, abutyl group, a pentyl group, a hexyl group, a heptyl group, an octylgroup, a nonyl group, a decyl group, a undecyl group, a dodecyl group, atridecyl group, a tetradecyl group, a pentadecyl group, a hexadecylgroup, a heptadecyl group, or an octadecyl group; or alternatively, amethyl group, an ethyl group, a propyl group, a butyl group, a pentylgroup, a hexyl group, a heptyl group, an octyl group, a nonyl group, ora decyl group. In some aspects, the alkyl group which can be an X informula (I) can be a methyl group, an ethyl group, a n-propyl group, aniso-propyl group, a n-butyl group, an iso-butyl group, a sec-butylgroup, a tert-butyl group, a n-pentyl group, an iso-pentyl group, asec-pentyl group, or a neopentyl group; alternatively, a methyl group,an ethyl group, an iso-propyl group, a tert-butyl group, or a neopentylgroup; alternatively, a methyl group; alternatively, an ethyl group;alternatively, a n-propyl group; alternatively, an iso-propyl group;alternatively, a tert-butyl group; or alternatively, a neopentyl group.

Suitable alkenyl groups which can be an X in formula (I) can include,but are not limited to, an ethenyl group, a propenyl group, a butenylgroup, a pentenyl group, a hexenyl group, a heptenyl group, an octenylgroup, a nonenyl group, a decenyl group, a undecenyl group, a dodecenylgroup, a tridecenyl group, a tetradecenyl group, a pentadecenyl group, ahexadecenyl group, a heptadecenyl group, or an octadecenyl group. Suchalkenyl groups can be linear or branched, and the double bond can belocated anywhere in the chain. In one aspect, each X in formula (I)independently can be an ethenyl group, a propenyl group, a butenylgroup, a pentenyl group, a hexenyl group, a heptenyl group, an octenylgroup, a nonenyl group, or a decenyl group, while in another aspect,each X in formula (I) independently can be an ethenyl group, a propenylgroup, a butenyl group, a pentenyl group, or a hexenyl group. Forexample, an X can be an ethenyl group; alternatively, a propenyl group;alternatively, a butenyl group; alternatively, a pentenyl group; oralternatively, a hexenyl group. In yet another aspect, an X can be aterminal alkenyl group, such as a C₃ to C₁₈ terminal alkenyl group, a C₃to C₁₂ terminal alkenyl group, or a C₃ to C₈ terminal alkenyl group.Illustrative terminal alkenyl groups can include, but are not limitedto, a prop-2-en-1-yl group, a bute-3-en-1-yl group, a pent-4-en-1-ylgroup, a hex-5-en-1-yl group, a hept-6-en-1-yl group, an octe-7-en-1-ylgroup, a non-8-en-1-yl group, a dece-9-en-1-yl group, and so forth.

Each X in formula (I) can be a cycloalkyl group, including, but notlimited to, a cyclobutyl group, a substituted cyclobutyl group, acyclopentyl group, a substituted cyclopentyl group, a cyclohexyl group,a substituted cyclohexyl group, a cycloheptyl group, a substitutedcycloheptyl group, a cyclooctyl group, or a substituted cyclooctylgroup. For example, an X in formula (I) can be a cyclopentyl group, asubstituted cyclopentyl group, a cyclohexyl group, or a substitutedcyclohexyl group. Moreover, each X in formula (I) independently can be acyclobutyl group or a substituted cyclobutyl group; alternatively, acyclopentyl group or a substituted cyclopentyl group; alternatively, acyclohexyl group or a substituted cyclohexyl group; alternatively, acycloheptyl group or a substituted cycloheptyl group; alternatively, acyclooctyl group or a substituted cyclooctyl group; alternatively, acyclopentyl group; alternatively, a substituted cyclopentyl group;alternatively, a cyclohexyl group; or alternatively, a substitutedcyclohexyl group. Substituents which can be utilized for the substitutedcycloalkyl group are independently disclosed herein and can be utilizedwithout limitation to further describe the substituted cycloalkyl groupwhich can be an X in formula (I).

In some aspects, the aryl group which can be an X in formula (I) can bea phenyl group, a substituted phenyl group, a naphthyl group, or asubstituted naphthyl group. In an aspect, the aryl group can be a phenylgroup or a substituted phenyl group; alternatively, a naphthyl group ora substituted naphthyl group; alternatively, a phenyl group or anaphthyl group; alternatively, a substituted phenyl group or asubstituted naphthyl group; alternatively, a phenyl group; oralternatively, a naphthyl group. Substituents which can be utilized forthe substituted phenyl groups or substituted naphthyl groups areindependently disclosed herein and can be utilized without limitation tofurther describe the substituted phenyl groups or substituted naphthylgroups which can be an X in formula (I).

In an aspect, the substituted phenyl group which can be an X in formula(I) can be a 2-substituted phenyl group, a 3-substituted phenyl group, a4-substituted phenyl group, a 2,4-disubstituted phenyl group, a2,6-disubstituted phenyl group, a 3,5-disubstituted phenyl group, or a2,4,6-trisubstituted phenyl group. In other aspects, the substitutedphenyl group can be a 2-substituted phenyl group, a 4-substituted phenylgroup, a 2,4-disubstituted phenyl group, or a 2,6-disubstituted phenylgroup; alternatively, a 3-substituted phenyl group or a3,5-disubstituted phenyl group; alternatively, a 2-substituted phenylgroup or a 4-substituted phenyl group; alternatively, a2,4-disubstituted phenyl group or a 2,6-disubstituted phenyl group;alternatively, a 2-substituted phenyl group; alternatively, a3-substituted phenyl group; alternatively, a 4-substituted phenyl group;alternatively, a 2,4-disubstituted phenyl group; alternatively, a2,6-disubstituted phenyl group; alternatively, a 3,5-disubstitutedphenyl group; or alternatively, a 2,4,6-trisubstituted phenyl group.Substituents which can be utilized for these specific substituted phenylgroups are independently disclosed herein and can be utilized withoutlimitation to further describe these substituted phenyl groups which canbe an X group(s) in formula (I).

In some aspects, the aralkyl group which can be an X group in formula(I) can be a benzyl group or a substituted benzyl group. In an aspect,the aralkyl group can be a benzyl group or, alternatively, a substitutedbenzyl group. Substituents which can be utilized for the substitutedaralkyl group are independently disclosed herein and can be utilizedwithout limitation to further describe the substituted aralkyl groupwhich can be an X group(s) in formula (I).

In an aspect, each non-hydrogen substituent(s) for the substitutedcycloalkyl group, substituted aryl group, or substituted aralkyl groupwhich can be an X in formula (I) independently can be a C₁ to C₁₈hydrocarbyl group; alternatively, a C₁ to C₈ hydrocarbyl group; oralternatively, a C₁ to C₅ hydrocarbyl group. Specific hydrocarbyl groupsare independently disclosed herein and can be utilized withoutlimitation to further describe the substituents of the substitutedcycloalkyl groups, substituted aryl groups, or substituted aralkylgroups which can be an X in formula (I). For instance, the hydrocarbylsubstituent can be an alkyl group, such as a methyl group, an ethylgroup, a n-propyl group, an isopropyl group, a n-butyl group, asec-butyl group, an isobutyl group, a tert-butyl group, a n-pentylgroup, a 2-pentyl group, a 3-pentyl group, a 2-methyl-1-butyl group, atert-pentyl group, a 3-methyl-1-butyl group, a 3-methyl-2-butyl group,or a neo-pentyl group, and the like. Furthermore, the hydrocarbylsubstituent can be a benzyl group, a phenyl group, a tolyl group, or axylyl group, and the like.

A hydrocarboxy group is used generically herein to include, forinstance, alkoxy, aryloxy, aralkoxy, -(alkyl, aryl, oraralkyl)-O-(alkyl, aryl, or aralkyl) groups, and —O(CO)-(hydrogen orhydrocarbyl) groups, and these groups can comprise up to about 36 carbonatoms (e.g., C₁ to C₃₆, C₁ to C₁₈, C₁ to C₁₀, or C₁ to C₈ hydrocarboxygroups). Illustrative and non-limiting examples of hydrocarboxy groupswhich can be an X in formula (I) can include, but are not limited to, amethoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group,an n-butoxy group, a sec-butoxy group, an isobutoxy group, a tert-butoxygroup, an n-pentoxy group, a 2-pentoxy group, a 3-pentoxy group, a2-methyl-1-butoxy group, a tert-pentoxy group, a 3-methyl-1-butoxygroup, a 3-methyl-2-butoxy group, a neo-pentoxy group, a phenoxy group,a toloxy group, a xyloxy group, a 2,4,6-trimethylphenoxy group, abenzoxy group, an acetylacetonate group (acac), a formate group, anacetate group, a stearate group, an oleate group, a benzoate group, andthe like. In an aspect, the hydrocarboxy group which can be an X informula (I) can be a methoxy group; alternatively, an ethoxy group;alternatively, an n-propoxy group; alternatively, an isopropoxy group;alternatively, an n-butoxy group; alternatively, a sec-butoxy group;alternatively, an isobutoxy group; alternatively, a tert-butoxy group;alternatively, an n-pentoxy group; alternatively, a 2-pentoxy group;alternatively, a 3-pentoxy group; alternatively, a 2-methyl-1-butoxygroup; alternatively, a tert-pentoxy group; alternatively, a3-methyl-1-butoxy group, alternatively, a 3-methyl-2-butoxy group;alternatively, a neo-pentoxy group; alternatively, a phenoxy group;alternatively, a toloxy group; alternatively, a xyloxy group;alternatively, a 2,4,6-trimethylphenoxy group; alternatively, a benzoxygroup; alternatively, an acetylacetonate group; alternatively, a formategroup; alternatively, an acetate group; alternatively, a stearate group;alternatively, an oleate group; or alternatively, a benzoate group.

The term hydrocarbylaminyl group is used generically herein to refercollectively to, for instance, alkylaminyl, arylaminyl, aralkylaminyl,dialkylaminyl, diarylaminyl, diaralkylaminyl, and -(alkyl, aryl, oraralkyl)-N-(alkyl, aryl, or aralkyl) groups, and unless otherwisespecified, the hydrocarbylaminyl groups which can be an X in formula (I)can comprise up to about 36 carbon atoms (e.g., C₁ to C₃₆, C₁ to C₁₈, C₁to C₁₀, or C₁ to C₈ hydrocarbylaminyl groups). Accordingly,hydrocarbylaminyl is intended to cover both (mono)hydrocarbylaminyl anddihydrocarbylaminyl groups. In some aspects, the hydrocarbylaminyl groupwhich can be an X in formula (I) can be, for instance, a methylaminylgroup (—NHCH₃), an ethylaminyl group (—NHCH₂CH₃), an n-propylaminylgroup (—NHCH₂CH₂CH₃), an iso-propylaminyl group (—NHCH(CH₃)₂), ann-butylaminyl group (—NHCH₂CH₂CH₂CH₃), a t-butylaminyl group(—NHC(CH₃)₃), an n-pentylaminyl group (—NHCH₂CH₂CH₂CH₂CH₃), aneo-pentylaminyl group (—NHCH₂C(CH₃)₃), a phenylaminyl group (—NHC₆H₅),a tolylaminyl group (—NHC₆H₄CH₃), or a xylylaminyl group(—NHC₆H₃(CH₃)₂); alternatively, a methylaminyl group; alternatively, anethylaminyl group; alternatively, a propylaminyl group; oralternatively, a phenylaminyl group. In other aspects, thehydrocarbylaminyl group which can be an X in formula (I) can be, forinstance, a dimethylaminyl group (—N(CH₃)₂), a diethylaminyl group(—N(CH₂CH₃)₂), a di-n-propylaminyl group (—N(CH₂CH₂CH₃)₂), adi-iso-propylaminyl group (—N(CH(CH₃)₂)₂), a di-n-butylaminyl group(—N(CH₂CH₂CH₂CH₃)₂), a di-t-butylaminyl group (—N(C(CH₃)₃)₂), adi-n-pentylaminyl group (—N(CH₂CH₂CH₂CH₂CH₃)₂), a di-neo-pentylaminylgroup (—N(CH₂C(CH₃)₃)₂), a di-phenylaminyl group (—N(C₆H₅)₂), adi-tolylaminyl group (—N(C₆H₄CH₃)₂), or a di-xylylaminyl group(—N(C₆H₃(CH₃)₂)₂); alternatively, a dimethylaminyl group; alternatively,a di-ethylaminyl group; alternatively, a di-n-propylaminyl group; oralternatively, a di-phenylaminyl group.

In accordance with some aspects disclosed herein, each X independentlycan be a C₁ to C₃₆ hydrocarbylsilyl group; alternatively, a C₁ to C₂₄hydrocarbylsilyl group; alternatively, a C₁ to C₁₈ hydrocarbylsilylgroup; or alternatively, a C₁ to C₈ hydrocarbylsilyl group. In anaspect, each hydrocarbyl (one or more) of the hydrocarbylsilyl group canbe any hydrocarbyl group disclosed herein (e.g., a C₁ to C₅ alkyl group,a C₂ to C₅ alkenyl group, a C₅ to C₈ cycloalkyl group, a C₆ to C₈ arylgroup, a C₇ to C₈ aralkyl group, etc.). As used herein, hydrocarbylsilylis intended to cover (mono)hydrocarbylsilyl (—SiH₂R), dihydrocarbylsilyl(—SiHR₂), and trihydrocarbylsilyl (—SiR₃) groups, with R being ahydrocarbyl group. In one aspect, the hydrocarbylsilyl group can be a C₃to C₃₆ or a C₃ to C₁₈ trihydrocarbylsilyl group, such as, for example, atrialkylsilyl group or a triphenylsilyl group. Illustrative andnon-limiting examples of hydrocarbylsilyl groups which can be an Xgroup(s) in formula (I) can include, but are not limited to,trimethylsilyl, triethylsilyl, tripropylsilyl (e.g., triisopropylsilyl),tributylsilyl, tripentylsilyl, triphenylsilyl, allyldimethylsilyl, andthe like.

A hydrocarbylaminylsilyl group is used herein to refer to groupscontaining at least one hydrocarbon moiety, at least one N atom, and atleast one Si atom. Illustrative and non-limiting examples ofhydrocarbylaminylsilyl groups which can be an X can include, but are notlimited to —N(SiMe₃)₂, —N(SiEt₃)₂, and the like. Unless otherwisespecified, the hydrocarbylaminylsilyl groups which can be X can compriseup to about 36 carbon atoms (e.g., C₁ to C₃₆, C₁ to C₁₈, C₁ to C₁₂, orC₁ to C₈ hydrocarbylaminylsilyl groups). In an aspect, each hydrocarbyl(one or more) of the hydrocarbylaminylsilyl group can be any hydrocarbylgroup disclosed herein (e.g., a C₁ to C₅ alkyl group, a C₂ to C₅ alkenylgroup, a C₅ to C₈ cycloalkyl group, a C₆ to C₈ aryl group, a C₇ to C₈aralkyl group, etc.). Moreover, hydrocarbylaminylsilyl is intended tocover —NH(SiH₂R), —NH(SiHR₂), —NH(SiR₃), —N(SiH₂R)₂, —N(SiHR₂)₂, and—N(SiR₃)₂ groups, among others, with R being a hydrocarbyl group.

In an aspect, each X independently can be —OBR¹ ₂ or —OSO₂R¹, wherein R¹is a C₁ to C₃₆ hydrocarbyl group, or alternatively, a C₁ to C₁₈hydrocarbyl group. The hydrocarbyl group in OBR¹ ₂ and/or OSO₂R¹independently can be any hydrocarbyl group disclosed herein, such as,for instance, a C₁ to C₁₈ alkyl group, a C₂ to C₁₈ alkenyl group, a C₄to C₁₈ cycloalkyl group, a C₆ to C₁₈ aryl group, or a C₇ to C₁₈ aralkylgroup; alternatively, a C₁ to C₁₂ alkyl group, a C₂ to C₁₂ alkenylgroup, a C₄ to C₁₂ cycloalkyl group, a C₆ to C₁₂ aryl group, or a C₇ toC₁₂ aralkyl group; or alternatively, a C₁ to C₈ alkyl group, a C₂ to C₈alkenyl group, a C₅ to C₈ cycloalkyl group, a C₆ to C₈ aryl group, or aC₇ to C₈ aralkyl group.

In one aspect, each X independently can be H, BH₄, a halide, or a C₁ toC₃₆ hydrocarbyl group, hydrocarboxy group, hydrocarbylaminyl group,hydrocarbylsilyl group, or hydrocarbylaminylsilyl group, while inanother aspect, each X independently can be H, BH₄, or a C₁ to C₁₈hydrocarboxy group, hydrocarbylaminyl group, hydrocarbylsilyl group, orhydrocarbylaminylsilyl group. In yet another aspect, each Xindependently can be a halide; alternatively, a C₁ to C₁₈ hydrocarbylgroup; alternatively, a C₁ to C₁₈ hydrocarboxy group; alternatively, aC₁ to C₁₈ hydrocarbylaminyl group; alternatively, a C₁ to C₁₈hydrocarbylsilyl group; or alternatively, a C₁ to C₁₈hydrocarbylaminylsilyl group. In still another aspect, each X can be H;alternatively, F; alternatively, Cl; alternatively, Br; alternatively,I; alternatively, BH₄; alternatively, a C₁ to C₁₈ hydrocarbyl group;alternatively, a C₁ to C₁₈ hydrocarboxy group; alternatively, a C₁ toC₁₈ hydrocarbylaminyl group; alternatively, a C₁ to C₁₈ hydrocarbylsilylgroup; or alternatively, a C₁ to C₁₈ hydrocarbylaminylsilyl group.

Each X independently can be, in some aspects, H, a halide, methyl,phenyl, benzyl, an alkoxy, an aryloxy, acetylacetonate, formate,acetate, stearate, oleate, benzoate, an alkylaminyl, a dialkylaminyl, atrihydrocarbylsilyl, or a hydrocarbylaminylsilyl; alternatively, H, ahalide, methyl, phenyl, or benzyl; alternatively, an alkoxy, an aryloxy,or acetylacetonate; alternatively, an alkylaminyl or a dialkylaminyl;alternatively, a trihydrocarbylsilyl or hydrocarbylaminylsilyl;alternatively, H or a halide; alternatively, methyl, phenyl, benzyl, analkoxy, an aryloxy, acetylacetonate, an alkylaminyl, or a dialkylaminyl;alternatively, H; alternatively, a halide; alternatively, methyl;alternatively, phenyl; alternatively, benzyl; alternatively, an alkoxy;alternatively, an aryloxy; alternatively, acetylacetonate;alternatively, an alkylaminyl; alternatively, a dialkylaminyl;alternatively, a trihydrocarbylsilyl; or alternatively, ahydrocarbylaminylsilyl. In these and other aspects, the alkoxy, aryloxy,alkylaminyl, dialkylaminyl, trihydrocarbylsilyl, andhydrocarbylaminylsilyl can be a C₁ to C₃₆, a C₁ to C₁₈, a C₁ to C₁₂, ora C₁ to C₈ alkoxy, aryloxy, alkylaminyl, dialkylaminyl,trihydrocarbylsilyl, and hydrocarbylaminylsilyl.

Moreover, each X independently can be, in certain aspects, a halide or aC₁ to C₁₈ hydrocarbyl group; alternatively, a halide or a C₁ to C₈hydrocarbyl group; alternatively, F, Cl, Br, I, methyl, benzyl, orphenyl; alternatively, Cl, methyl, benzyl, or phenyl; alternatively, aC₁ to C₁₈ alkoxy, aryloxy, alkylaminyl, dialkylaminyl,trihydrocarbylsilyl, or hydrocarbylaminylsilyl group; alternatively, aC₁ to C₈ alkoxy, aryloxy, alkylaminyl, dialkylaminyl,trihydrocarbylsilyl, or hydrocarbylaminylsilyl group; or alternatively,methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl,decyl, ethenyl, propenyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl,nonenyl, decenyl, phenyl, tolyl, benzyl, naphthyl, trimethylsilyl,triisopropylsilyl, triphenylsilyl, or allyldimethylsilyl.

In formula (I), Cp^(A) and Cp^(B) independently can be a substituted orunsubstituted cyclopentadienyl or indenyl group. In one aspect, Cp^(A)and Cp^(B) independently can be an unsubstituted cyclopentadienyl orindenyl group. Alternatively, Cp^(A) and Cp^(B) independently can be asubstituted indenyl or cyclopentadienyl group, for example, having up to5 substituents.

If present, each substituent on Cp^(A) and Cp^(B) independently can beH, a halide, a C₁ to C₃₆ hydrocarbyl group, a C₁ to C₃₆ halogenatedhydrocarbyl group, a C₁ to C₃₆ hydrocarboxy group, or a C₁ to C₃₆hydrocarbylsilyl group. Importantly, each substituent on Cp^(A) and/orCp^(B) can be either the same or a different substituent group.Moreover, each substituent can be at any position on the respectivecyclopentadienyl or indenyl ring structure that conforms with the rulesof chemical valence. In an aspect, the number of substituents on Cp^(A)and/or on Cp^(B) and/or the positions of each substituent on Cp^(A)and/or on Cp^(B) are independent of each other. For instance, two ormore substituents on Cp^(A) can be different, or alternatively, eachsubstituent on Cp^(A) can be the same. Additionally or alternatively,two or more substituents on Cp^(B) can be different, or alternatively,all substituents on Cp^(B) can be the same. In another aspect, one ormore of the substituents on Cp^(A) can be different from the one or moreof the substituents on Cp^(B), or alternatively, all substituents onboth Cp^(A) and/or on Cp^(B) can be the same. In these and otheraspects, each substituent can be at any position on the respectivecyclopentadienyl or indenyl ring structure. If substituted, Cp^(A)and/or Cp^(B) independently can have one substituent, two substituents,three substituents, four substituents, and so forth.

In formula (I), each substituent on Cp^(A) and/or on Cp^(B)independently can be H, a halide, a C₁ to C₃₆ hydrocarbyl group, a C₁ toC₃₆ halogenated hydrocarbyl group, a C₁ to C₃₆ hydrocarboxy group, or aC₁ to C₃₆ hydrocarbylsilyl group. In some aspects, each substituentindependently can be H; alternatively, a halide; alternatively, a C₁ toC₁₈ hydrocarbyl group; alternatively, a C₁ to C₁₈ halogenatedhydrocarbyl group; alternatively, a C₁ to C₁₈ hydrocarboxy group;alternatively, a C₁ to C₁₈ hydrocarbylsilyl group; alternatively, a C₁to C₁₂ hydrocarbyl group or a C₁ to C₁₂ hydrocarbylsilyl group; oralternatively, a C₁ to C₈ alkyl group or a C₃ to C₈ alkenyl group. Thehalide, C₁ to C₃₆ hydrocarbyl group, C₁ to C₃₆ hydrocarboxy group, andC₁ to C₃₆ hydrocarbylsilyl group which can be a substituent on Cp^(A)and/or on Cp^(B) in formula (I) can be any halide, C₁ to C₃₆ hydrocarbylgroup, C₁ to C₃₆ hydrocarboxy group, and C₁ to C₃₆ hydrocarbylsilylgroup described herein (e.g., as pertaining to X in formula (I)). Asubstituent on Cp^(A) and/or on Cp^(B) in formula (I) can be, in certainaspects, a C₁ to C₃₆ halogenated hydrocarbyl group, where thehalogenated hydrocarbyl group indicates the presence of one or morehalogen atoms replacing an equivalent number of hydrogen atoms in thehydrocarbyl group. The halogenated hydrocarbyl group often can be ahalogenated alkyl group, a halogenated alkenyl group, a halogenatedcycloalkyl group, a halogenated aryl group, or a halogenated aralkylgroup. Representative and non-limiting halogenated hydrocarbyl groupsinclude pentafluorophenyl, trifluoromethyl (CF₃), and the like.

As a non-limiting example, if present, each substituent on Cp^(A) and/orCp^(B) independently can be H, Cl, CF₃, a methyl group, an ethyl group,a propyl group, a butyl group (e.g., t-Bu), a pentyl group, a hexylgroup, a heptyl group, an octyl group, a nonyl group, a decyl group, anethenyl group, a propenyl group, a butenyl group, a pentenyl group, ahexenyl group, a heptenyl group, an octenyl group, a nonenyl group, adecenyl group, a phenyl group, a tolyl group (or other substituted arylgroup), a benzyl group, a naphthyl group, a trimethylsilyl group, atriisopropylsilyl group, a triphenylsilyl group, or anallyldimethylsilyl group; alternatively, H; alternatively, Cl;alternatively, CF₃; alternatively, a methyl group; alternatively, anethyl group; alternatively, a propyl group; alternatively, a butylgroup; alternatively, a pentyl group; alternatively, a hexyl group;alternatively, a heptyl group; alternatively, an octyl group, a nonylgroup; alternatively, a decyl group; alternatively, an ethenyl group;alternatively, a propenyl group; alternatively, a butenyl group;alternatively, a pentenyl group; alternatively, a hexenyl group;alternatively, a heptenyl group; alternatively, an octenyl group;alternatively, a nonenyl group; alternatively, a decenyl group;alternatively, a phenyl group; alternatively, a tolyl group;alternatively, a benzyl group; alternatively, a naphthyl group;alternatively, a trimethylsilyl group; alternatively, atriisopropylsilyl group; alternatively, a triphenylsilyl group; oralternatively, an allyldimethylsilyl group.

Illustrative and non-limiting examples of unbridged metallocenecompounds having formula (I) and/or suitable for use as catalystcomponent I can include the following compounds (Ph=phenyl):

and the like, as well as combinations thereof.

Catalyst component I is not limited solely to unbridged metallocenecompounds such as described above, or to suitable unbridged metallocenecompounds disclosed in U.S. Pat. Nos. 7,199,073, 7,226,886, 7,312,283,and 7,619,047, which are incorporated herein by reference in theirentirety. For example, catalyst component I can comprise an unbridgedzirconium and/or hafnium based dinuclear metallocene compound. In oneaspect, catalyst component I can comprise an unbridged zirconium basedhomodinuclear metallocene compound. In another aspect, catalystcomponent I can comprise an unbridged hafnium based homodinuclearmetallocene compound. In yet another aspect, catalyst component I cancomprise an unbridged zirconium and/or hafnium based heterodinuclearmetallocene compound (i.e., dinuclear compound with two hafniums, or twozirconiums, or one zirconium and one hafnium). Catalyst component I cancomprise unbridged dinuclear metallocenes such as those described inU.S. Pat. Nos. 7,919,639 and 8,080,681, the disclosures of which areincorporated herein by reference in their entirety. Illustrative andnon-limiting examples of dinuclear metallocene compounds suitable foruse as catalyst component I can include the following compounds:

and the like, as well as combinations thereof.Catalyst Component II

Catalyst component II can comprise a bridged metallocene compound. Inone aspect, for instance, catalyst component II can comprise a bridgedzirconium or hafnium based metallocene compound. In another aspect,catalyst component II can comprise a bridged zirconium or hafnium basedmetallocene compound with an alkenyl substituent. In yet another aspect,catalyst component II can comprise a bridged zirconium or hafnium basedmetallocene compound with an alkenyl substituent and a fluorenyl group.In still another aspect, catalyst component II can comprise a bridgedzirconium or hafnium based metallocene compound with a cyclopentadienylgroup and a fluorenyl group, and with an alkenyl substituent on thebridging group and/or on the cyclopentadienyl group.

In some aspects, catalyst component II can comprise a bridgedmetallocene compound having an aryl group substituent on the bridginggroup, while in other aspects, catalyst component II can comprise adinuclear bridged metallocene compound with an alkenyl linking group.

Catalyst component II can comprise, in particular aspects of thisinvention, a bridged metallocene compound having formula (II):

Within formula (II), M, Cp, R^(X), R^(Y), E, and each X are independentelements of the bridged metallocene compound. Accordingly, the bridgedmetallocene compound having formula (II) can be described using anycombination of M, Cp, R^(X), R^(Y), E, and X disclosed herein.

The selections for M and each X in formula (II) are the same as thosedescribed herein above for formula (I). In formula (II), Cp can be asubstituted cyclopentadienyl, indenyl, or fluorenyl group. In oneaspect, Cp can be a substituted cyclopentadienyl group, while in anotheraspect, Cp can be a substituted indenyl group.

In some aspects, Cp can contain no additional substituents, e.g., otherthan bridging group E, discussed further herein below. In other aspects,Cp can be further substituted with one substituent, two substituents,three substituents, four substituents, and so forth. If present, eachsubstituent on Cp independently can be H, a halide, a C₁ to C₃₆hydrocarbyl group, a C₁ to C₃₆ halogenated hydrocarbyl group, a C₁ toC₃₆ hydrocarboxy group, or a C₁ to C₃₆ hydrocarbylsilyl group.Importantly, each substituent on Cp can be either the same or adifferent substituent group. Moreover, each substituent can be at anyposition on the respective cyclopentadienyl, indenyl, or fluorenyl ringstructure that conforms with the rules of chemical valence. In general,any substituent on Cp, independently, can be H or any halide, C₁ to C₃₆hydrocarbyl group, C₁ to C₃₆ halogenated hydrocarbyl group, C₁ to C₃₆hydrocarboxy group, or C₁ to C₃₆ hydrocarbylsilyl group described herein(e.g., as pertaining to substituents on Cp^(A) and Cp^(B) in formula(I)).

In one aspect, for example, each substituent on Cp independently can bea C₁ to C₁₂ hydrocarbyl group or a C₁ to C₁₂ hydrocarbylsilyl group. Inanother aspect, each substituent on Cp independently can be a C₁ to C₈alkyl group or a C₃ to C₈ alkenyl group. In yet another aspect, eachsubstituent on Cp^(C) independently can be H, Cl, CF₃, a methyl group,an ethyl group, a propyl group, a butyl group, a pentyl group, a hexylgroup, a heptyl group, an octyl group, a nonyl group, a decyl group, anethenyl group, a propenyl group, a butenyl group, a pentenyl group, ahexenyl group, a heptenyl group, an octenyl group, a nonenyl group, adecenyl group, a phenyl group, a tolyl group, a benzyl group, a naphthylgroup, a trimethylsilyl group, a triisopropylsilyl group, atriphenylsilyl group, or an allyldimethylsilyl group.

Similarly, R^(X) and R^(Y) in formula (II) independently can be H or anyhalide, C₁ to C₃₆ hydrocarbyl group, C₁ to C₃₆ halogenated hydrocarbylgroup, C₁ to C₃₆ hydrocarboxy group, or C₁ to C₃₆ hydrocarbylsilyl groupdisclosed herein (e.g., as pertaining to substituents on Cp^(A) andCp^(B) in formula (I)). In one aspect, for example, R^(X) and R^(Y)independently can be H or a C₁ to C₁₂ hydrocarbyl group. In anotheraspect, R^(X) and R^(Y) independently can be a C₁ to C₁₀ hydrocarbylgroup. In yet another aspect, R^(X) and R^(Y) independently can be H,Cl, CF₃, a methyl group, an ethyl group, a propyl group, a butyl group(e.g., t-Bu), a pentyl group, a hexyl group, a heptyl group, an octylgroup, a nonyl group, a decyl group, an ethenyl group, a propenyl group,a butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, anoctenyl group, a nonenyl group, a decenyl group, a phenyl group, a tolylgroup, a benzyl group, a naphthyl group, a trimethylsilyl group, atriisopropylsilyl group, a triphenylsilyl group, or anallyldimethylsilyl group, and the like. In still another aspect, R^(X)and R^(Y) independently can be a methyl group, an ethyl group, a propylgroup, a butyl group, a pentyl group, a hexyl group, a heptyl group, anoctyl group, a nonyl group, a decyl group, an ethenyl group, a propenylgroup, a butenyl group, a pentenyl group, a hexenyl group, a heptenylgroup, an octenyl group, a nonenyl group, a decenyl group, a phenylgroup, a tolyl group, or a benzyl group.

Bridging group E in formula (II) can be (i) a bridging group having theformula >E^(A)R^(A)R^(B), wherein E^(A) can be C, Si, or Ge, and R^(A)and R^(B) independently can be H or a C₁ to C₁₈ hydrocarbyl group; (ii)a bridging group having the formula —CR^(C)R^(D)—CR^(E)R^(F)—, whereinR^(C), R^(D), R^(E), and R^(F) independently can be H or a C₁ to C₁₈hydrocarbyl group; or (iii) a bridging group having the formula—SiR^(G)R^(H)-E⁵R^(I)R^(J)—, wherein E⁵ can be C or Si, and R^(G),R^(H), R^(I), and R^(J) independently can be H or a C₁ to C₁₈hydrocarbyl group.

In the first option, the bridging group E can have the formula>E^(A)R^(A)R^(B), wherein E^(A) can be C, Si, or Ge, and R^(A) and R^(B)independently can be H or any C₁ to C₁₈ hydrocarbyl group disclosedherein. In some aspects of this invention, R^(A) and R^(B) independentlycan be a C₁ to C₁₂ hydrocarbyl group; alternatively, R^(A) and R^(B)independently can be a C₁ to C₈ hydrocarbyl group; alternatively, R^(A)and R^(B) independently can be a phenyl group, a C₁ to C₈ alkyl group,or a C₃ to C₈ alkenyl group; alternatively, R^(A) and R^(B)independently can be a methyl group, an ethyl group, a propyl group, abutyl group, a pentyl group, a hexyl group, a heptyl group, an octylgroup, a nonyl group, a decyl group, an ethenyl group, a propenyl group,a butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, anoctenyl group, a nonenyl group, a decenyl group, a phenyl group, acyclohexylphenyl group, a naphthyl group, a tolyl group, or a benzylgroup; or alternatively, R^(A) and R^(B) independently can be a methylgroup, an ethyl group, a propyl group, a butyl group, a pentyl group, ahexyl group, a propenyl group, a butenyl group, a pentenyl group, ahexenyl group, a phenyl group, or a benzyl group. In these and otheraspects, R^(A) and R^(B) can be either the same or different.

In the second option, the bridging group E can have the formula—CR^(C)R^(D)—CR^(E)R^(F)—, wherein R^(C), R^(D), R^(E), and R^(F)independently can be H or any C₁ to C₁₈ hydrocarbyl group disclosedherein. For instance, R^(C), R^(D), R^(E), and R^(F) independently canbe H or a methyl group.

In the third option, the bridging group E can have the formula—SiR^(G)R^(H)-E⁵R^(I)R^(J)—, wherein E⁵ can be C or Si, and R^(G),R^(H), R^(I), and R^(J) independently can be H or any C₁ to C₁₈hydrocarbyl group disclosed herein. For instance, E⁵ can be Si, andR^(G), R^(H), R^(I), and R^(J) independently can be H or a methyl group.

Illustrative and non-limiting examples of bridged metallocene compoundshaving formula (II) and/or suitable for use as catalyst component II caninclude the following compounds (Me=methyl, Ph=phenyl; t-Bu=tert-butyl):

and the like, as well as combinations thereof.

Further examples of bridged metallocene compounds having formula (II)and/or suitable for use as catalyst component II can include, but arenot limited to, the following compounds:

and the like, as well as combinations thereof.

Catalyst component II is not limited solely to the bridged metallocenecompounds such as described above. Other suitable bridged metallocenecompounds are disclosed in U.S. Pat. Nos. 7,026,494, 7,041,617,7,226,886, 7,312,283, 7,517,939, and 7,619,047, which are incorporatedherein by reference in their entirety.

Activator-Supports

The present invention encompasses various catalyst compositionscontaining an activator-support. In one aspect, the activator-supportcan comprise a solid oxide treated with an electron-withdrawing anion.Alternatively, in another aspect, the activator-support can comprise asolid oxide treated with an electron-withdrawing anion, the solid oxidecontaining a Lewis-acidic metal ion. Non-limiting examples of suitableactivator-supports are disclosed in, for instance, U.S. Pat. Nos.7,294,599, 7,601,665, 7,884,163, 8,309,485, and 8,623,973, which areincorporated herein by reference in their entirety.

The solid oxide can encompass oxide materials such as alumina, “mixedoxides” thereof such as silica-alumina, coatings of one oxide onanother, and combinations and mixtures thereof. The mixed oxides such assilica-alumina can be single or multiple chemical phases with more thanone metal combined with oxygen to form the solid oxide. Examples ofmixed oxides that can be used to form an activator-support, eithersingly or in combination, can include, but are not limited to,silica-alumina, silica-titania, silica-zirconia, alumina-titania,alumina-zirconia, zinc-aluminate, alumina-boria, silica-boria,aluminophosphate-silica, titania-zirconia, and the like. The solid oxideused herein also can encompass oxide materials such as silica-coatedalumina, as described in U.S. Pat. No. 7,884,163.

Accordingly, in one aspect, the solid oxide can comprise silica,alumina, silica-alumina, silica-coated alumina, aluminum phosphate,aluminophosphate, heteropolytungstate, titania, silica-titania,zirconia, silica-zirconia, magnesia, boria, zinc oxide, any mixed oxidethereof, or any combination thereof. In another aspect, the solid oxidecan comprise alumina, silica-alumina, silica-coated alumina, aluminumphosphate, aluminophosphate, heteropolytungstate, titania,silica-titania, zirconia, silica-zirconia, magnesia, boria, or zincoxide, as well as any mixed oxide thereof, or any mixture thereof. Inanother aspect, the solid oxide can comprise silica, alumina, titania,zirconia, magnesia, boria, zinc oxide, any mixed oxide thereof, or anycombination thereof. In yet another aspect, the solid oxide can comprisesilica-alumina, silica-coated alumina, silica-titania, silica-zirconia,alumina-boria, or any combination thereof. In still another aspect, thesolid oxide can comprise alumina, silica-alumina, silica-coated alumina,or any mixture thereof, alternatively, alumina; alternatively,silica-alumina; or alternatively, silica-coated alumina.

The silica-alumina or silica-coated alumina solid oxide materials whichcan be used can have an silica content from about 5 to about 95% byweight. In one aspect, the silica content of these solid oxides can befrom about 10 to about 80%, or from about 20% to about 70%, silica byweight. In another aspect, such materials can have silica contentsranging from about 15% to about 60%, or from about 25% to about 50%,silica by weight. The solid oxides contemplated herein can have anysuitable surface area, pore volume, and particle size, as would berecognized by those of skill in the art.

The electron-withdrawing component used to treat the solid oxide can beany component that increases the Lewis or Brønsted acidity of the solidoxide upon treatment (as compared to the solid oxide that is not treatedwith at least one electron-withdrawing anion). According to one aspect,the electron-withdrawing component can be an electron-withdrawing anionderived from a salt, an acid, or other compound, such as a volatileorganic compound, that serves as a source or precursor for that anion.Examples of electron-withdrawing anions can include, but are not limitedto, sulfate, bisulfate, fluoride, chloride, bromide, iodide,fluorosulfate, fluoroborate, phosphate, fluorophosphate,trifluoroacetate, triflate, fluorozirconate, fluorotitanate,phospho-tungstate, tungstate, molybdate, and the like, includingmixtures and combinations thereof. In addition, other ionic or non-ioniccompounds that serve as sources for these electron-withdrawing anionsalso can be employed. It is contemplated that the electron-withdrawinganion can be, or can comprise, fluoride, chloride, bromide, phosphate,triflate, bisulfate, or sulfate, and the like, or any combinationthereof, in some aspects provided herein. In other aspects, theelectron-withdrawing anion can comprise sulfate, bisulfate, fluoride,chloride, bromide, iodide, fluorosulfate, fluoroborate, phosphate,fluorophosphate, trifluoroacetate, triflate, fluorozirconate,fluorotitanate, and the like, or combinations thereof. Yet, in otheraspects, the electron-withdrawing anion can comprise fluoride and/orsulfate.

The activator-support generally can contain from about 1 to about 25 wt.% of the electron-withdrawing anion, based on the weight of theactivator-support. In particular aspects provided herein, theactivator-support can contain from about 1 to about 20 wt. %, from about2 to about 20 wt. %, from about 3 to about 20 wt. %, from about 2 toabout 15 wt. %, from about 3 to about 15 wt. %, from about 3 to about 12wt. %, or from about 4 to about 10 wt. %, of the electron-withdrawinganion, based on the total weight of the activator-support.

In an aspect, the activator-support can comprise fluorided alumina,chlorided alumina, bromided alumina, sulfated alumina, fluoridedsilica-alumina, chlorided silica-alumina, bromided silica-alumina,sulfated silica-alumina, fluorided silica-zirconia, chloridedsilica-zirconia, bromided silica-zirconia, sulfated silica-zirconia,fluorided silica-titania, fluorided silica-coated alumina, sulfatedsilica-coated alumina, phosphated silica-coated alumina, and the like,as well as any mixture or combination thereof. In another aspect, theactivator-support employed in the catalyst systems described herein canbe, or can comprise, a fluorided solid oxide and/or a sulfated solidoxide, non-limiting examples of which can include fluorided alumina,sulfated alumina, fluorided silica-alumina, sulfated silica-alumina,fluorided silica-zirconia, fluorided silica-coated alumina, sulfatedsilica-coated alumina, and the like, as well as combinations thereof. Inyet another aspect, the activator-support can comprise fluoridedalumina; alternatively, chlorided alumina; alternatively, sulfatedalumina; alternatively, fluorided silica-alumina; alternatively,sulfated silica-alumina; alternatively, fluorided silica-zirconia;alternatively, chlorided silica-zirconia; alternatively, sulfatedsilica-coated alumina; or alternatively, fluorided silica-coatedalumina.

Various processes can be used to form activator-supports useful in thepresent invention. Methods of contacting the solid oxide with theelectron-withdrawing component, suitable electron withdrawing componentsand addition amounts, impregnation with metals or metal ions (e.g.,zinc, nickel, vanadium, titanium, silver, copper, gallium, tin,tungsten, molybdenum, zirconium, and the like, or combinations thereof),and various calcining procedures and conditions are disclosed in, forexample, U.S. Pat. Nos. 6,107,230, 6,165,929, 6,294,494, 6,300,271,6,316,553, 6,355,594, 6,376,415, 6,388,017, 6,391,816, 6,395,666,6,524,987, 6,548,441, 6,548,442, 6,576,583, 6,613,712, 6,632,894,6,667,274, 6,750,302, 7,294,599, 7,601,665, 7,884,163, and 8,309,485,which are incorporated herein by reference in their entirety. Othersuitable processes and procedures for preparing activator-supports(e.g., fluorided solid oxides, sulfated solid oxides, etc.) are wellknown to those of skill in the art.

Co-Catalysts

In certain aspects directed to catalyst compositions containing aco-catalyst, the co-catalyst can comprise a metal hydrocarbyl compound,examples of which include non-halide metal hydrocarbyl compounds, metalhydrocarbyl halide compounds, non-halide metal alkyl compounds, metalalkyl halide compounds, and so forth. The hydrocarbyl group (or alkylgroup) can be any hydrocarbyl (or alkyl) group disclosed herein.Moreover, in some aspects, the metal of the metal hydrocarbyl can be agroup 1, 2, 11, 12, 13, or 14 metal; alternatively, a group 13 or 14metal; or alternatively, a group 13 metal. Hence, in some aspects, themetal of the metal hydrocarbyl (non-halide metal hydrocarbyl or metalhydrocarbyl halide) can be lithium, sodium, potassium, rubidium, cesium,beryllium, magnesium, calcium, strontium, barium, zinc, cadmium, boron,aluminum, or tin; alternatively, lithium, sodium, potassium, magnesium,calcium, zinc, boron, aluminum, or tin; alternatively, lithium, sodium,or potassium; alternatively, magnesium or calcium; alternatively,lithium; alternatively, sodium; alternatively, potassium; alternatively,magnesium; alternatively, calcium; alternatively, zinc; alternatively,boron; alternatively, aluminum; or alternatively, tin. In some aspects,the metal hydrocarbyl or metal alkyl, with or without a halide, cancomprise a lithium hydrocarbyl or alkyl, a magnesium hydrocarbyl oralkyl, a boron hydrocarbyl or alkyl, a zinc hydrocarbyl or alkyl, or analuminum hydrocarbyl or alkyl.

In particular aspects directed to catalyst compositions containing aco-catalyst (e.g., the activator can comprise a solid oxide treated withan electron-withdrawing anion), the co-catalyst can comprise analuminoxane compound, an organoboron or organoborate compound, anionizing ionic compound, an organoaluminum compound, an organozinccompound, an organomagnesium compound, or an organolithium compound, andthis includes any combinations of these materials. In one aspect, theco-catalyst can comprise an organoaluminum compound. In another aspect,the co-catalyst can comprise an aluminoxane compound, an organoboron ororganoborate compound, an ionizing ionic compound, an organozinccompound, an organomagnesium compound, an organolithium compound, or anycombination thereof. In yet another aspect, the co-catalyst can comprisean aluminoxane compound; alternatively, an organoboron or organoboratecompound; alternatively, an ionizing ionic compound; alternatively, anorganozinc compound; alternatively, an organomagnesium compound; oralternatively, an organolithium compound.

Specific non-limiting examples of suitable organoaluminum compounds caninclude trimethylaluminum (TMA), triethylaluminum (TEA),tri-n-propylaluminum (TNPA), tri-n-butylaluminum (TNBA),triisobutylaluminum (TIBA), tri-n-hexylaluminum, tri-n-octylaluminum,diisobutylaluminum hydride, diethylaluminum ethoxide, diethylaluminumchloride, and the like, or combinations thereof. Representative andnon-limiting examples of aluminoxanes include methylaluminoxane,modified methylaluminoxane, ethylaluminoxane, n-propylaluminoxane,iso-propylaluminoxane, n-butylaluminoxane, t-butylaluminoxane,sec-butylaluminoxane, iso-butylaluminoxane, 1-pentylaluminoxane,2-pentylaluminoxane, 3-pentylaluminoxane, isopentylaluminoxane,neopentylaluminoxane, and the like, or any combination thereof.Representative and non-limiting examples of organoboron/organoboratecompounds include N,N-dimethylaniliniumtetrakis(pentafluorophenyl)borate, triphenylcarbeniumtetrakis(pentafluorophenyl)borate, lithiumtetrakis(pentafluorophenyl)borate, N,N-dimethylaniliniumtetrakis[3,5-bis(trifluoromethyl)phenyl]borate, triphenylcarbeniumtetrakis[3,5-bis(trifluoromethyl)phenyl]borate,tris(pentafluorophenyl)boron, tris[3,5-bis(trifluoromethyl)phenyl]boron,and the like, or mixtures thereof.

Examples of ionizing ionic compounds can include, but are not limitedto, the following compounds: tri(n-butyl)ammoniumtetrakis(p-tolyl)borate, tri(n-butyl) ammonium tetrakis(m-tolyl)borate,tri(n-butyl)ammonium tetrakis(2,4-dimethylphenyl)borate,tri(n-butyl)ammonium tetrakis(3,5-dimethylphenyl)borate,tri(n-butyl)ammonium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate,tri(n-butyl)ammonium tetrakis(pentafluorophenyl)borate,N,N-dimethylanilinium tetrakis(p-tolyl)borate, N,N-dimethylaniliniumtetrakis(m-tolyl)borate, N,N-dimethylaniliniumtetrakis(2,4-dimethylphenyl)borate, N,N-dimethylaniliniumtetrakis(3,5-dimethyl-phenyl)borate, N,N-dimethylaniliniumtetrakis[3,5-bis(trifluoromethyl)phenyl]borate, N,N-dimethylaniliniumtetrakis(pentafluorophenyl)borate, triphenylcarbeniumtetrakis(p-tolyl)borate, triphenylcarbenium tetrakis(m-tolyl)borate,triphenylcarbenium tetrakis(2,4-dimethylphenyl)borate,triphenylcarbenium tetrakis(3,5-dimethylphenyl)borate,triphenylcarbenium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate,triphenylcarbenium tetrakis(pentafluorophenyl)borate, tropyliumtetrakis(p-tolyl)borate, tropylium tetrakis(m-tolyl)borate, tropyliumtetrakis(2,4-dimethylphenyl)borate, tropyliumtetrakis(3,5-dimethylphenyl)borate, tropyliumtetrakis[3,5-bis(trifluoromethyl)phenyl]borate, tropyliumtetrakis(pentafluorophenyl) borate, lithiumtetrakis(pentafluorophenyl)borate, lithium tetraphenylborate, lithiumtetrakis(p-tolyl)borate, lithium tetrakis(m-tolyl)borate, lithiumtetrakis(2,4-dimethylphenyl)borate, lithiumtetrakis(3,5-dimethylphenyl)borate, lithium tetrafluoroborate, sodiumtetrakis(pentafluorophenyl)borate, sodium tetraphenylborate, sodiumtetrakis(p-tolyl)borate, sodium tetrakis(m-tolyl)borate, sodiumtetrakis(2,4-dimethylphenyl)borate, sodiumtetrakis(3,5-dimethylphenyl)borate, sodium tetrafluoroborate, potassiumtetrakis(pentafluorophenyl)borate, potassium tetraphenylborate,potassium tetrakis(p-tolyl)borate, potassium tetrakis(m-tolyl)borate,potassium tetrakis(2,4-dimethylphenyl)borate, potassiumtetrakis(3,5-dimethylphenyl)borate, potassium tetrafluoroborate, lithiumtetrakis(pentafluorophenyl)aluminate, lithium tetraphenylaluminate,lithium tetrakis(p-tolyl)aluminate, lithium tetrakis(m-tolyl)aluminate,lithium tetrakis(2,4-dimethylphenyl)aluminate, lithiumtetrakis(3,5-dimethylphenyl)aluminate, lithium tetrafluoroaluminate,sodium tetrakis(pentafluorophenyl)aluminate, sodiumtetraphenylaluminate, sodium tetrakis(p-tolyl)aluminate, sodiumtetrakis(m-tolyl)aluminate, sodiumtetrakis(2,4-dimethylphenyl)aluminate, sodiumtetrakis(3,5-dimethylphenyl)aluminate, sodium tetrafluoroaluminate,potassium tetrakis(pentafluorophenyl)aluminate, potassiumtetraphenylaluminate, potassium tetrakis(p-tolyl)aluminate, potassiumtetrakis(m-tolyl)aluminate, potassiumtetrakis(2,4-dimethylphenyl)aluminate, potassium tetrakis(3,5-dimethylphenyl)aluminate, potassium tetrafluoroaluminate, and thelike, or combinations thereof.

Exemplary organozinc compounds which can be used as co-catalysts caninclude, but are not limited to, dimethylzinc, diethylzinc,dipropylzinc, dibutylzinc, dineopentylzinc, di(trimethylsilyl)zinc,di(triethylsilyl)zinc, di(triisoproplysilyl)zinc,di(triphenylsilyl)zinc, di(allyldimethylsilyl)zinc,di(trimethylsilylmethyl)zinc, and the like, or combinations thereof.

Similarly, exemplary organomagnesium compounds can include, but are notlimited to, dimethylmagnesium, diethylmagnesium, dipropylmagnesium,dibutylmagnesium, dineopentylmagnesium,di(trimethylsilylmethyl)magnesium, methylmagnesium chloride,ethylmagnesium chloride, propylmagnesium chloride, butylmagnesiumchloride, neopentylmagnesium chloride, trimethylsilylmethylmagnesiumchloride, methylmagnesium bromide, ethylmagnesium bromide,propylmagnesium bromide, butylmagnesium bromide, neopentylmagnesiumbromide, trimethylsilylmethylmagnesium bromide, methylmagnesium iodide,ethylmagnesium iodide, propylmagnesium iodide, butylmagnesium iodide,neopentylmagnesium iodide, trimethylsilylmethylmagnesium iodide,methylmagnesium ethoxide, ethylmagnesium ethoxide, propylmagnesiumethoxide, butylmagnesium ethoxide, neopentylmagnesium ethoxide,trimethylsilylmethylmagnesium ethoxide, methylmagnesium propoxide,ethylmagnesium propoxide, propylmagnesium propoxide, butylmagnesiumpropoxide, neopentylmagnesium propoxide, trimethylsilylmethylmagnesiumpropoxide, methylmagnesium phenoxide, ethylmagnesium phenoxide,propylmagnesium phenoxide, butylmagnesium phenoxide, neopentylmagnesiumphenoxide, trimethylsilylmethylmagnesium phenoxide, and the like, or anycombinations thereof.

Likewise, exemplary organolithium compounds can include, but are notlimited to, methyllithium, ethyllithium, propyllithium, butyllithium(e.g., t-butyllithium), neopentyllithium, trimethylsilylmethyllithium,phenyllithium, tolyllithium, xylyllithium, benzyllithium,(dimethylphenyl)methyllithium, allyllithium, and the like, orcombinations thereof.

Co-catalysts that can be used in the catalyst compositions of thisinvention are not limited to the co-catalysts described above. Othersuitable co-catalysts are well known to those of skill in the artincluding, for example, those disclosed in U.S. Pat. Nos. 3,242,099,4,794,096, 4,808,561, 5,576,259, 5,807,938, 5,919,983, 7,294,5997,601,665, 7,884,163, 8,114,946, and 8,309,485, which are incorporatedherein by reference in their entirety.

Olefin Monomers

Unsaturated reactants that can be employed with catalyst compositionsand polymerization processes of this invention typically can includeolefin compounds having from 2 to 30 carbon atoms per molecule andhaving at least one olefinic double bond. This invention encompasseshomopolymerization processes using a single olefin such as ethylene orpropylene, as well as copolymerization, terpolymerization, etc.,reactions using an olefin monomer with at least one different olefiniccompound. For example, the resultant ethylene copolymers, terpolymers,etc., generally can contain a major amount of ethylene (>50 molepercent) and a minor amount of comonomer (<50 mole percent), though thisis not a requirement. Comonomers that can be copolymerized with ethyleneoften can have from 3 to 20 carbon atoms, or from 3 to 10 carbon atoms,in their molecular chain.

Acyclic, cyclic, polycyclic, terminal (α), internal, linear, branched,substituted, unsubstituted, functionalized, and non-functionalizedolefins can be employed in this invention. For example, typicalunsaturated compounds that can be polymerized with the catalystcompositions of this invention can include, but are not limited to,ethylene, propylene, 1-butene, 2-butene, 3-methyl-1-butene, isobutylene,1-pentene, 2-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 1-hexene,2-hexene, 3-hexene, 3-ethyl-1-hexene, 1-heptene, 2-heptene, 3-heptene,the four normal octenes (e.g., 1-octene), the four normal nonenes, thefive normal decenes, and the like, or mixtures of two or more of thesecompounds. Cyclic and bicyclic olefins, including but not limited to,cyclopentene, cyclohexene, norbornylene, norbornadiene, and the like,also can be polymerized as described herein. Styrene can also beemployed as a monomer in the present invention. In an aspect, the olefinmonomer can comprise a C₂-C₂₀ olefin; alternatively, a C₂-C₂₀alpha-olefin; alternatively, a C₂-C₁₀ olefin; alternatively, a C₂-C₁₀alpha-olefin; alternatively, the olefin monomer can comprise ethylene;or alternatively, the olefin monomer can comprise propylene.

When a copolymer (or alternatively, a terpolymer) is desired, the olefinmonomer and the olefin comonomer independently can comprise, forexample, a C₂-C₂₀ alpha-olefin. In some aspects, the olefin monomer cancomprise ethylene or propylene, which is copolymerized with at least onecomonomer (e.g., a C₂-C₂₀ alpha-olefin, a C₃-C₂₀ alpha-olefin, etc.).According to one aspect of this invention, the olefin monomer used inthe polymerization process can comprise ethylene. In this aspect,examples of suitable olefin comonomers can include, but are not limitedto, propylene, 1-butene, 2-butene, 3-methyl-1-butene, isobutylene,1-pentene, 2-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 1-hexene,2-hexene, 3-ethyl-1-hexene, 1-heptene, 2-heptene, 3-heptene, 1-octene,1-decene, styrene, and the like, or combinations thereof. According toanother aspect of the present invention, the olefin monomer can compriseethylene, and the comonomer can comprise a C₃-C₁₀ alpha-olefin;alternatively, the comonomer can comprise 1-butene, 1-pentene, 1-hexene,1-octene, 1-decene, styrene, or any combination thereof; alternatively,the comonomer can comprise 1-butene, 1-hexene, 1-octene, or anycombination thereof; alternatively, the comonomer can comprise 1-butene;alternatively, the comonomer can comprise 1-hexene; or alternatively,the comonomer can comprise 1-octene.

Generally, the amount of comonomer introduced into a polymerizationreactor system to produce a copolymer can be from about 0.01 to about 50weight percent of the comonomer based on the total weight of the monomerand comonomer. According to another aspect of the present invention, theamount of comonomer introduced into a polymerization reactor system canbe from about 0.01 to about 40 weight percent comonomer based on thetotal weight of the monomer and comonomer. In still another aspect, theamount of comonomer introduced into a polymerization reactor system canbe from about 0.1 to about 35 weight percent comonomer based on thetotal weight of the monomer and comonomer. Yet, in another aspect, theamount of comonomer introduced into a polymerization reactor system canbe from about 0.5 to about 20 weight percent comonomer based on thetotal weight of the monomer and comonomer.

While not intending to be bound by this theory, where branched,substituted, or functionalized olefins are used as reactants, it isbelieved that a steric hindrance can impede and/or slow thepolymerization process. Thus, branched and/or cyclic portion(s) of theolefin removed somewhat from the carbon-carbon double bond would not beexpected to hinder the reaction in the way that the same olefinsubstituents situated more proximate to the carbon-carbon double bondmight.

According to one aspect of the present invention, at least onemonomer/reactant can be ethylene (or propylene), so the polymerizationreaction can be a homopolymerization involving only ethylene (orpropylene), or a copolymerization with a different acyclic, cyclic,terminal, internal, linear, branched, substituted, or unsubstitutedolefin. In addition, the catalyst compositions of this invention can beused in the polymerization of diolefin compounds including, but notlimited to, 1,3-butadiene, isoprene, 1,4-pentadiene, and 1,5-hexadiene.

Catalyst Compositions

In some aspects, the present invention can employ catalyst compositionscontaining catalyst component I, catalyst component II, an activator(one or more than one), and optionally, a co-catalyst. These catalystcompositions can be utilized to produce polyolefins—homopolymers,copolymers, and the like—for a variety of end-use applications. Catalystcomponents I are II are discussed hereinabove. In aspects of the presentinvention, it is contemplated that the catalyst composition can containmore than one catalyst component I metallocene compound, and/or morethan one catalyst component II metallocene compound. Further, additionalcatalytic compounds—other than those specified as catalyst component Ior II—can be employed in the catalyst compositions and/or thepolymerization processes, provided that the additional catalyticcompound(s) does not detract from the advantages disclosed herein.Additionally, more than one activator also may be utilized.

The metallocene compounds of catalyst component I are discussedhereinabove. For instance, in some aspects, catalyst component I cancomprise (or consist essentially of, or consist of) an unbridgedmetallocene compound having formula (I). The bridged metallocenecompounds of catalyst component II also are discussed hereinabove. Forinstance, in some aspects, catalyst component II can comprise (orconsist essentially of, or consist of) a metallocene compound havingformula (II).

Generally, catalyst compositions of the present invention can comprisecatalyst component I, catalyst component II, and an activator. Inaspects of the invention, the activator can comprise anactivator-support (e.g., an activator-support comprising a solid oxidetreated with an electron-withdrawing anion). Activator-supports usefulin the present invention are disclosed hereinabove. Optionally, suchcatalyst compositions can further comprise one or more than oneco-catalyst compound or compounds (suitable co-catalysts, such asorganoaluminum compounds, also are discussed hereinabove). Thus, acatalyst composition of this invention can comprise catalyst componentI, catalyst component II, an activator-support, and an organoaluminumcompound. For instance, the activator-support can comprise (or consistessentially of, or consist of) fluorided alumina, chlorided alumina,bromided alumina, sulfated alumina, fluorided silica-alumina, chloridedsilica-alumina, bromided silica-alumina, sulfated silica-alumina,fluorided silica-zirconia, chlorided silica-zirconia, bromidedsilica-zirconia, sulfated silica-zirconia, fluorided silica-titania,fluorided silica-coated alumina, sulfated silica-coated alumina,phosphated silica-coated alumina, and the like, or combinations thereof;alternatively, the activator-support can comprise (or consistessentially of, or consist of) a fluorided solid oxide and/or a sulfatedsolid oxide. Additionally, the organoaluminum compound can comprise (orconsist essentially of, or consist of) trimethylaluminum,triethylaluminum, tri-n-propylaluminum, tri-n-butylaluminum,triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum,diisobutylaluminum hydride, diethylaluminum ethoxide, diethylaluminumchloride, and the like, or combinations thereof. Accordingly, a catalystcomposition consistent with aspects of the invention can comprise (orconsist essentially of, or consist of) an unbridged zirconium or hafniumbased metallocene compound; a bridged zirconium or hafnium basedmetallocene compound with a fluorenyl group; sulfated alumina (orfluorided silica-alumina, or fluorided silica-coated alumina); andtriethylaluminum (or triisobutylaluminum).

In another aspect of the present invention, a catalyst composition isprovided which comprises catalyst component I, catalyst component II, anactivator-support, and an organoaluminum compound, wherein this catalystcomposition is substantially free of aluminoxanes, organoboron ororganoborate compounds, ionizing ionic compounds, and/or other similarmaterials; alternatively, substantially free of aluminoxanes;alternatively, substantially free or organoboron or organoboratecompounds; or alternatively, substantially free of ionizing ioniccompounds. In these aspects, the catalyst composition has catalystactivity, discussed below, in the absence of these additional materials.For example, a catalyst composition of the present invention can consistessentially of catalyst component I, catalyst component II, anactivator-support, and an organoaluminum compound, wherein no othermaterials are present in the catalyst composition which wouldincrease/decrease the activity of the catalyst composition by more thanabout 10% from the catalyst activity of the catalyst composition in theabsence of said materials.

However, in other aspects of this invention, theseactivators/co-catalysts can be employed. For example, a catalystcomposition comprising catalyst component I, catalyst component II, andan activator-support can further comprise an optional co-catalyst.Suitable co-catalysts in this aspect can include, but are not limitedto, aluminoxane compounds, organoboron or organoborate compounds,ionizing ionic compounds, organoaluminum compounds, organozinccompounds, organomagnesium compounds, organolithium compounds, and thelike, or any combination thereof; or alternatively, organoaluminumcompounds, organozinc compounds, organomagnesium compounds,organolithium compounds, or any combination thereof. More than oneco-catalyst can be present in the catalyst composition.

In a different aspect, a catalyst composition is provided which does notrequire an activator-support. Such a catalyst composition can comprisecatalyst component I, catalyst component II, and an activator, whereinthe activator comprises an aluminoxane compound, an organoboron ororganoborate compound, an ionizing ionic compound, or combinationsthereof.

In a particular aspect contemplated herein, the catalyst composition isa catalyst composition comprising an activator (one or more than one),only one catalyst component I metallocene compound, and only onecatalyst component II metallocene compound. In these and other aspects,the catalyst composition can comprise an activator (e.g., anactivator-support comprising a solid oxide treated with anelectron-withdrawing anion); only one unbridged zirconium or hafniumbased metallocene compound; and only one bridged zirconium or hafniumbased metallocene compound with a fluorenyl group.

This invention further encompasses methods of making these catalystcompositions, such as, for example, contacting the respective catalystcomponents in any order or sequence.

According to an aspect of this invention, the weight ratio of catalystcomponent I to catalyst component II in the catalyst composition can bein a range from about 10:1 to about 1:10, from about 8:1 to about 1:8,from about 5:1 to about 1:5, from about 4:1 to about 1:4, from about 3:1to about 1:3; from about 2:1 to about 1:2, from about 1.5:1 to about1:1.5, from about 1.25:1 to about 1:1.25, or from about 1.1:1 to about1:1.1.

Generally, the weight ratio of organoaluminum compound toactivator-support can be in a range from about 10:1 to about 1:1000. Ifmore than one organoaluminum compound and/or more than oneactivator-support are employed, this ratio is based on the total weightof each respective component. In another aspect, the weight ratio of theorganoaluminum compound to the activator-support can be in a range fromabout 3:1 to about 1:100, or from about 1:1 to about 1:50.

In some aspects of this invention, the weight ratio of metallocenecompounds (total of catalyst component I and II) to activator-supportcan be in a range from about 1:1 to about 1:1,000,000. If more than oneactivator-support is employed, this ratio is based on the total weightof the activator-support. In another aspect, this weight ratio can be ina range from about 1:5 to about 1:100,000, or from about 1:10 to about1:10,000. Yet, in another aspect, the weight ratio of the metallocenecompounds to the activator-support can be in a range from about 1:20 toabout 1:1000.

Catalyst compositions of the present invention generally have a catalystactivity greater than about 100 grams of polyethylene (homopolymer,copolymer, etc., as the context requires) per gram of activator-supportper hour (abbreviated g/g/hr). In another aspect, the catalyst activitycan be greater than about 150, greater than about 250, or greater thanabout 500 g/g/hr. In still another aspect, catalyst compositions of thisinvention can be characterized by having a catalyst activity greaterthan about 550, greater than about 650, or greater than about 750g/g/hr. Yet, in another aspect, the catalyst activity can be greaterthan about 1000 g/g/hr, greater than about 2000 g/g/hr, or greater thanabout 3000 g/g/hr, and often as high as 5000-10,000 g/g/hr. Illustrativeand non-limiting ranges for the catalyst activity include from about 150to about 10,000, from about 500 to about 7,500, or from about 1,000 toabout 5,000 g/g/hr, and the like. These activities are measured underslurry polymerization conditions, with a triisobutylaluminumco-catalyst, using isobutane as the diluent, at a polymerizationtemperature of about 90° C. and a reactor pressure of about 390 psig.Moreover, in some aspects, the activator-support can comprise sulfatedalumina, fluorided silica-alumina, or fluorided silica-coated alumina,although not limited thereto.

Polymerization Processes

Catalyst compositions of the present invention can be used to polymerizeolefins to form homopolymers, copolymers, terpolymers, and the like. Onesuch process for polymerizing olefins in the presence of a catalystcomposition of the present invention can comprise contacting thecatalyst composition with an olefin monomer and optionally an olefincomonomer (one or more) in a polymerization reactor system underpolymerization conditions to produce an olefin polymer, wherein thecatalyst composition can comprise catalyst component I, catalystcomponent II, an activator, and an optional co-catalyst. Catalystcomponents I and II are discussed herein. For instance, catalystcomponent I can comprise an unbridged metallocene compound havingformula (I), and catalyst component II can comprise a bridgedmetallocene compound having formula (II).

In accordance with one aspect of the invention, the polymerizationprocess can employ a catalyst composition comprising catalyst componentI, catalyst component II, and an activator, wherein the activatorcomprises an activator-support. Activator-supports useful in thepolymerization processes of the present invention are disclosed herein.The catalyst composition, optionally, can further comprise one or morethan one organoaluminum compound or compounds (or other suitableco-catalyst). Thus, a process for polymerizing olefins in the presenceof a catalyst composition can employ a catalyst composition comprisingcatalyst component I, catalyst component II, an activator-support, andan organoaluminum compound. In some aspects, the activator-support cancomprise (or consist essentially of, or consist of) fluorided alumina,chlorided alumina, bromided alumina, sulfated alumina, fluoridedsilica-alumina, chlorided silica-alumina, bromided silica-alumina,sulfated silica-alumina, fluorided silica-zirconia, chloridedsilica-zirconia, bromided silica-zirconia, sulfated silica-zirconia,fluorided silica-titania, fluorided silica-coated alumina, sulfatedsilica-coated alumina, phosphated silica-coated alumina, and the like,or combinations thereof; or alternatively a fluorided solid oxide and/ora sulfated solid oxide. In some aspects, the organoaluminum compound cancomprise (or consist essentially of, or consist of) trimethylaluminum,triethylaluminum, tri-n-propylaluminum, tri-n-butylaluminum,triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum,diisobutylaluminum hydride, diethylaluminum ethoxide, diethylaluminumchloride, and the like, or combinations thereof.

In accordance with another aspect of the invention, the polymerizationprocess can employ a catalyst composition comprising catalyst componentI, catalyst component II, an activator-support, and an optionalco-catalyst, wherein the co-catalyst can comprise an aluminoxanecompound, an organoboron or organoborate compound, an ionizing ioniccompound, an organoaluminum compound, an organozinc compound, anorganomagnesium compound, or an organolithium compound, or anycombination thereof. Hence, aspects of this invention are directed to aprocess for polymerizing olefins in the presence of a catalystcomposition, the processes comprising contacting a catalyst compositionwith an olefin monomer and optionally an olefin comonomer (one or more)under polymerization conditions to produce an olefin polymer, and thecatalyst composition can comprise catalyst component I, catalystcomponent II, an activator-support, and an aluminoxane compound;alternatively, catalyst component I, catalyst component II, anactivator-support, and an organoboron or organoborate compound;alternatively, catalyst component I, catalyst component II, anactivator-support, and an ionizing ionic compound; alternatively,catalyst component I, catalyst component II, an activator-support, andan organoaluminum compound; alternatively, catalyst component I,catalyst component II, an activator-support, and an organozinc compound;alternatively, catalyst component I, catalyst component II, anactivator-support, and an organomagnesium compound; or alternatively,catalyst component I, catalyst component II, an activator-support, andan organolithium compound. Furthermore, more than one co-catalyst can beemployed, e.g., an organoaluminum compound and an aluminoxane compound,an organoaluminum compound and an ionizing ionic compound, etc.

In accordance with another aspect of the invention, the polymerizationprocess can employ a catalyst composition comprising only one catalystcomponent I metallocene compound, only one catalyst component IImetallocene compound, an activator-support, and an organoaluminumcompound.

In accordance with yet another aspect of the invention, thepolymerization process can employ a catalyst composition comprisingcatalyst component I, catalyst component II, and an activator, whereinthe activator comprises an aluminoxane compound, an organoboron ororganoborate compound, an ionizing ionic compound, or combinationsthereof.

The catalyst compositions of the present invention are intended for anyolefin polymerization method using various types of polymerizationreactor systems and reactors. The polymerization reactor system caninclude any polymerization reactor capable of polymerizing olefinmonomers and comonomers (one or more than one comonomer) to producehomopolymers, copolymers, terpolymers, and the like. The various typesof reactors include those that can be referred to as a batch reactor,slurry reactor, gas-phase reactor, solution reactor, high pressurereactor, tubular reactor, autoclave reactor, and the like, orcombinations thereof. Suitable polymerization conditions are used forthe various reactor types. Gas phase reactors can comprise fluidized bedreactors or staged horizontal reactors. Slurry reactors can comprisevertical or horizontal loops. High pressure reactors can compriseautoclave or tubular reactors. Reactor types can include batch orcontinuous processes. Continuous processes can use intermittent orcontinuous product discharge. Processes can also include partial or fulldirect recycle of unreacted monomer, unreacted comonomer, and/ordiluent.

Polymerization reactor systems of the present invention can comprise onetype of reactor in a system or multiple reactors of the same ordifferent type (e.g., a single reactor, dual reactor, more than tworeactors). Production of polymers in multiple reactors can includeseveral stages in at least two separate polymerization reactorsinterconnected by a transfer device making it possible to transfer thepolymers resulting from the first polymerization reactor into the secondreactor. The desired polymerization conditions in one of the reactorscan be different from the operating conditions of the other reactor(s).Alternatively, polymerization in multiple reactors can include themanual transfer of polymer from one reactor to subsequent reactors forcontinued polymerization. Multiple reactor systems can include anycombination including, but not limited to, multiple loop reactors,multiple gas phase reactors, a combination of loop and gas phasereactors, multiple high pressure reactors, or a combination of highpressure with loop and/or gas phase reactors. The multiple reactors canbe operated in series, in parallel, or both. Accordingly, the presentinvention encompasses polymerization reactor systems comprising a singlereactor, comprising two reactors, and comprising more than two reactors.The polymerization reactor system can comprise a slurry reactor, agas-phase reactor, a solution reactor, in certain aspects of thisinvention, as well as multi-reactor combinations thereof.

According to one aspect of the invention, the polymerization reactorsystem can comprise at least one loop slurry reactor comprising verticalor horizontal loops. Monomer, diluent, catalyst, and comonomer can becontinuously fed to a loop reactor where polymerization occurs.Generally, continuous processes can comprise the continuous introductionof monomer/comonomer, a catalyst, and a diluent into a polymerizationreactor and the continuous removal from this reactor of a suspensioncomprising polymer particles and the diluent. Reactor effluent can beflashed to remove the solid polymer from the liquids that comprise thediluent, monomer and/or comonomer. Various technologies can be used forthis separation step including, but not limited to, flashing that caninclude any combination of heat addition and pressure reduction,separation by cyclonic action in either a cyclone or hydrocyclone, orseparation by centrifugation.

A typical slurry polymerization process (also known as the particle formprocess) is disclosed, for example, in U.S. Pat. Nos. 3,248,179,4,501,885, 5,565,175, 5,575,979, 6,239,235, 6,262,191, and 6,833,415,each of which is incorporated herein by reference in its entirety.

Suitable diluents used in slurry polymerization include, but are notlimited to, the monomer being polymerized and hydrocarbons that areliquids under polymerization conditions. Examples of suitable diluentsinclude, but are not limited to, hydrocarbons such as propane,cyclohexane, isobutane, n-butane, n-pentane, isopentane, neopentane, andn-hexane. Some loop polymerization reactions can occur under bulkconditions where no diluent is used. An example is polymerization ofpropylene monomer as disclosed in U.S. Pat. No. 5,455,314, which isincorporated by reference herein in its entirety.

According to yet another aspect of this invention, the polymerizationreactor system can comprise at least one gas phase reactor. Such systemscan employ a continuous recycle stream containing one or more monomerscontinuously cycled through a fluidized bed in the presence of thecatalyst under polymerization conditions. A recycle stream can bewithdrawn from the fluidized bed and recycled back into the reactor.Simultaneously, polymer product can be withdrawn from the reactor andnew or fresh monomer can be added to replace the polymerized monomer.Such gas phase reactors can comprise a process for multi-step gas-phasepolymerization of olefins, in which olefins are polymerized in thegaseous phase in at least two independent gas-phase polymerization zoneswhile feeding a catalyst-containing polymer formed in a firstpolymerization zone to a second polymerization zone. One type of gasphase reactor is disclosed in U.S. Pat. Nos. 5,352,749, 4,588,790, and5,436,304, each of which is incorporated by reference in its entiretyherein.

According to still another aspect of the invention, a high pressurepolymerization reactor can comprise a tubular reactor or an autoclavereactor. Tubular reactors can have several zones where fresh monomer,initiators, or catalysts are added. Monomer can be entrained in an inertgaseous stream and introduced at one zone of the reactor. Initiators,catalysts, and/or catalyst components can be entrained in a gaseousstream and introduced at another zone of the reactor. The gas streamscan be intermixed for polymerization. Heat and pressure can be employedappropriately to obtain optimal polymerization reaction conditions.

According to yet another aspect of the invention, the polymerizationreactor system can comprise a solution polymerization reactor whereinthe monomer (and comonomer, if used) are contacted with the catalystcomposition by suitable stirring or other means. A carrier comprising aninert organic diluent or excess monomer can be employed. If desired, themonomer/comonomer can be brought in the vapor phase into contact withthe catalytic reaction product, in the presence or absence of liquidmaterial. The polymerization zone is maintained at temperatures andpressures that will result in the formation of a solution of the polymerin a reaction medium. Agitation can be employed to obtain bettertemperature control and to maintain uniform polymerization mixturesthroughout the polymerization zone. Adequate means are utilized fordissipating the exothermic heat of polymerization.

Polymerization reactor systems suitable for the present invention canfurther comprise any combination of at least one raw material feedsystem, at least one feed system for catalyst or catalyst components,and/or at least one polymer recovery system. Suitable reactor systemsfor the present invention can further comprise systems for feedstockpurification, catalyst storage and preparation, extrusion, reactorcooling, polymer recovery, fractionation, recycle, storage, loadout,laboratory analysis, and process control.

Polymerization conditions that are controlled for efficiency and toprovide desired polymer properties can include temperature, pressure,and the concentrations of various reactants. Polymerization temperaturecan affect catalyst productivity, polymer molecular weight, andmolecular weight distribution. A suitable polymerization temperature canbe any temperature below the de-polymerization temperature according tothe Gibbs Free energy equation. Typically, this includes from about 60°C. to about 280° C., for example, or from about 60° C. to about 120° C.,depending upon the type of polymerization reactor(s). In some reactorsystems, the polymerization temperature generally can fall within arange from about 70° C. to about 100° C., or from about 75° C. to about95° C. Various polymerization conditions can be held substantiallyconstant, for example, for the production of a particular grade ofolefin polymer.

Suitable pressures will also vary according to the reactor andpolymerization type. The pressure for liquid phase polymerizations in aloop reactor is typically less than 1000 psig (6.9 MPa). Pressure forgas phase polymerization is usually at about 200 to 500 psig (1.4 MPa to3.4 MPa). High pressure polymerization in tubular or autoclave reactorsis generally run at about 20,000 to 75,000 psig (138 to 517 MPa).Polymerization reactors can also be operated in a supercritical regionoccurring at generally higher temperatures and pressures. Operationabove the critical point of a pressure/temperature diagram(supercritical phase) may offer advantages.

Aspects of this invention are directed to olefin polymerizationprocesses comprising contacting a catalyst composition with an olefinmonomer and an optional olefin comonomer under polymerization conditionsto produce an olefin polymer. The olefin polymer (e.g., ethylenecopolymer) produced by the process can have any of the polymerproperties disclosed herein, for example, a density of greater than orequal to about 0.945 g/cm³, and/or a high load melt index (HLMI) in arange from about 1 to about 25 g/10 min, and/or a peak molecular weight(Mp) in a range from about 52,000 to about 132,000 g/mol, and/or anenvironmental stress crack resistance (ESCR) of at least 250 hours,and/or a weight-average molecular weight (Mw) in a range from about275,000 to about 800,000 g/mol, and/or a number-average molecular weight(Mn) in a range from about 20,000 to about 60,000 g/mol, and/or a ratioof Mw/Mn in a range from about 5 to about 22, and/or low levels of longchain branches (LCB), and/or a reverse comonomer distribution, and/or abimodal molecular weight distribution.

Aspects of this invention also are directed to olefin polymerizationprocesses conducted in the absence of added hydrogen. An olefinpolymerization process of this invention can comprise contacting acatalyst composition with an olefin monomer and optionally an olefincomonomer in a polymerization reactor system under polymerizationconditions to produce an olefin polymer, wherein the catalystcomposition can comprise catalyst component I, catalyst component II, anactivator, and an optional co-catalyst, and wherein the polymerizationprocess is conducted in the absence of added hydrogen (no hydrogen isadded to the polymerization reactor system). As one of ordinary skill inthe art would recognize, hydrogen can be generated in-situ bymetallocene catalyst compositions in various olefin polymerizationprocesses, and the amount generated can vary depending upon the specificcatalyst composition and metallocene compound(s) employed, the type ofpolymerization process used, the polymerization reaction conditionsutilized, and so forth.

In other aspects, it may be desirable to conduct the polymerizationprocess in the presence of a certain amount of added hydrogen.Accordingly, an olefin polymerization process of this invention cancomprise contacting a catalyst composition with an olefin monomer andoptionally an olefin comonomer in a polymerization reactor system underpolymerization conditions to produce an olefin polymer, wherein thecatalyst composition comprises catalyst component I, catalyst componentII, an activator, and an optional co-catalyst, and wherein thepolymerization process is conducted in the presence of added hydrogen(hydrogen is added to the polymerization reactor system). For example,the ratio of hydrogen to the olefin monomer in the polymerizationprocess can be controlled, often by the feed ratio of hydrogen to theolefin monomer entering the reactor. The added hydrogen to olefinmonomer ratio in the process can be controlled at a weight ratio whichfalls within a range from about 25 ppm to about 1500 ppm, from about 50to about 1000 ppm, or from about 100 ppm to about 750 ppm.

In some aspects of this invention, the feed or reactant ratio ofhydrogen to olefin monomer can be maintained substantially constantduring the polymerization run for a particular polymer grade. That is,the hydrogen:olefin monomer ratio can be selected at a particular ratiowithin a range from about 5 ppm up to about 1000 ppm or so, andmaintained at the ratio to within about +/−25% during the polymerizationrun. For instance, if the target ratio is 100 ppm, then maintaining thehydrogen:olefin monomer ratio substantially constant would entailmaintaining the feed ratio between about 75 ppm and about 125 ppm.Further, the addition of comonomer (or comonomers) can be, and generallyis, substantially constant throughout the polymerization run for aparticular polymer grade.

However, in other aspects, it is contemplated that monomer, comonomer(or comonomers), and/or hydrogen can be periodically pulsed to thereactor, for instance, in a manner similar to that employed in U.S. Pat.No. 5,739,220 and U.S. Patent Publication No. 2004/0059070, thedisclosures of which are incorporated herein by reference in theirentirety.

The concentration of the reactants entering the polymerization reactorsystem can be controlled to produce resins with certain physical andmechanical properties. The proposed end-use product that will be formedby the polymer resin and the method of forming that product ultimatelycan determine the desired polymer properties and attributes. Mechanicalproperties include tensile, flexural, impact, creep, stress relaxation,and hardness tests. Physical properties include density, molecularweight, molecular weight distribution, melting temperature, glasstransition temperature, temperature melt of crystallization, density,stereoregularity, crack growth, long chain branching, and rheologicalmeasurements.

This invention is also directed to, and encompasses, the polymers (e.g.,ethylene/α-olefin copolymers) produced by any of the polymerizationprocesses disclosed herein. Articles of manufacture can be formed from,and/or can comprise, the polymers produced in accordance with thisinvention.

Polymers and Articles

Certain aspects of this invention are directed to improved polyolefinresins for blow molding applications, as compared to conventional resinsproduced using chromium-based catalyst systems. Conventionalchromium-based resins for blow molding applications generally have abroad MWD, acceptable die/weight swell, high melt strength and hangtime, and overall excellent processability on a wide range of blowmolding machinery. Notwithstanding these benefits, improvements intoughness, impact strength, and ESCR are desired. Olefin polymersdescribed herein, in certain aspects, can provide a unique combinationof the ease of processing typically associated with conventionalchromium-based resins (e.g., acceptable die/weight swell, high meltstrength and hang time, etc.), along with improvements in toughness,impact strength, and ESCR over conventional chromium-based resins. Suchimprovements can result in blow molded parts or articles with longerlifetimes, and may allow processors the opportunity to downgauge orthin-wall the blow molded parts or articles, resulting in decreasedresin usage and cost reduction.

Olefin polymers encompassed herein can include any polymer produced fromany olefin monomer and comonomer(s) described herein. For example, theolefin polymer can comprise an ethylene homopolymer, a propylenehomopolymer, an ethylene copolymer (e.g., ethylene/α-olefin,ethylene/1-butene, ethylene/1-hexene, ethylene/1-octene, etc.), apropylene copolymer, an ethylene terpolymer, a propylene terpolymer, andthe like, including combinations thereof. In one aspect, the olefinpolymer can be an ethylene/1-butene copolymer, an ethylene/1-hexenecopolymer, or an ethylene/1-octene copolymer, while in another aspect,the olefin polymer can be an ethylene/1-hexene copolymer.

If the resultant polymer produced in accordance with the presentinvention is, for example, an ethylene polymer, its properties can becharacterized by various analytical techniques known and used in thepolyolefin industry. Articles of manufacture can be formed from, and/orcan comprise, the ethylene polymers of this invention, whose typicalproperties are provided below.

An illustrative and non-limiting example of an ethylene polymer of thepresent invention can have a density of greater than or equal to about0.945 g/cm³, a high load melt index (HLMI) in a range from about 1 toabout 25 g/10 min, a peak molecular weight (Mp) in a range from about52,000 to about 132,000 g/mol, and an environmental stress crackresistance (ESCR) of at least 250 hours. Another illustrative andnon-limiting example of an ethylene polymer of the present invention canhave a density of greater than or equal to about 0.945 g/cm³, a highload melt index (HLMI) in a range from about 1 to about 25 g/10 min, aweight-average molecular weight (Mw) in a range from about 275,000 toabout 800,000 g/mol, a number-average molecular weight (Mn) in a rangefrom about 20,000 to about 60,000 g/mol, and a ratio of Mw/Mn in a rangefrom about 5 to about 22. These illustrative and non-limiting examplesof ethylene polymers consistent with the present invention also can haveany of the polymer properties listed below and in any combination.

Polymers of ethylene (homopolymers, copolymers, etc.) produced inaccordance with some aspects of this invention generally can have a meltindex (MI) from 0 to about 0.6 g/10 min. Melt indices in the range from0 to about 0.5, from 0 to about 0.25, from 0 to about 0.2, or from 0 toabout 0.15 g/10 min, are contemplated in other aspects of thisinvention. For example, a polymer of the present invention can have a MIin a range from 0 to about 0.1, or from 0 to about 0.05 g/10 min.

Consistent with certain aspects of this invention, ethylene polymersdescribed herein can have a high load melt index (HLMI) in a range fromabout 1 to about 25, from about 1 to about 20, from about 2 to about 25,or from about 2 to about 20 g/10 min. In further aspects, ethylenepolymers described herein can have a HLMI in a range from about 1 toabout 15, from about 2 to about 15, from about 1 to about 10, or fromabout 2 to about 10 g/10 min.

The densities of ethylene-based polymers produced using the catalystsystems and processes disclosed herein often are greater than or equalto about 0.94 g/cm³, for example, greater than or equal to about 0.945,greater than or equal to about 0.948, or greater than or equal to about0.952 g/cm³, and often can range up to about 0.968 g/cm³. Yet, inparticular aspects, the density can be in a range from about 0.945 toabout 0.965, such as, for example, from about 0.947 to about 0.962, fromabout 0.95 to about 0.965, from about 0.952 to about 0.962, or fromabout 0.952 to about 0.96 g/cm³.

Generally, polymers produced in aspects of the present invention areessentially linear or have very low levels of long chain branching, withtypically less than about 0.01 long chain branches (LCB) per 1000 totalcarbon atoms, and similar in LCB content to polymers shown, for example,in U.S. Pat. Nos. 7,517,939, 8,114,946, and 8,383,754, which areincorporated herein by reference in their entirety. In other aspects,the number of LCB per 1000 total carbon atoms can be less than about0.008, less than about 0.007, less than about 0.005, or less than about0.003 LCB per 1000 total carbon atoms. These LCB contents are for the500,000 to 5,000,000 g/mol molecular weight range of the polymer, usingthe analytical procedure described herein.

Consistent with aspects of this disclosure, ethylene polymers can havean environmental stress crack resistance (ESCR) of at least 250 hours.Moreover, in some aspects, the ethylene polymers described herein canhave an ESCR of at least 500 hours, at least 750 hours, at least 1,000hours, at least 1,500 hours, at least 1,750 hours, or at least 2,000hours, and often can range as high as 2,500 to 4,000 hours. The ESCRtest is typically stopped after a certain number of hours is reached,and given the long duration of the test, the upper limit of ESCR (inhours) is generally not determined. ESCR testing and test resultsdisclosed herein are in accordance with ASTM D1693, condition B, 10%igepal, which is a much more stringent test than ESCR testing conductedusing a 100% igepal solution.

Often, the ethylene polymer can have a Tensile Impact of greater than orequal to about 400, greater than or equal to about 450, greater than orequal to about 500, greater than or equal to about 550, or greater thanor equal to about 600 kJ/m². Representative non-limiting ranges includethe following: from about 400 to about 1000, from about 400 to about800, from about 450 to about 1000, from about 450 to about 800, fromabout 500 to about 1000, from about 500 to about 800, or from about 600to about 1000 kJ/m², and the like. In some aspects, the ethylenepolymers of this invention can have a Charpy Impact in a range fromabout 25 to about 75, from about 30 to about 80, from about 25 to about70, from about 30 to about 70, from about 30 to about 65, from about 28to about 68, or from about 32 to about 72 kJ/m².

Ethylene copolymers, for example, produced using the polymerizationprocesses and catalyst systems described hereinabove can, in someaspects, have a reverse comonomer distribution, generally, the highermolecular weight components of the polymer have higher comonomerincorporation than the lower molecular weight components. Typically,there is increasing comonomer incorporation with increasing molecularweight. In one aspect, the number of short chain branches (SCB) per 1000total carbon atoms of the polymer can be greater at Mw than at Mn. Inanother aspect, the number of SCB per 1000 total carbon atoms of thepolymer can be greater at Mz than at Mw. In yet another aspect, thenumber of SCB per 1000 total carbon atoms of the polymer can be greaterat Mz than at Mn. In still another aspect, the number of SCB per 1000total carbon atoms of the polymer at a molecular weight of 10⁶ can begreater than at a molecular weight of 10⁵.

Ethylene polymers, such as homopolymers, copolymers, etc., consistentwith various aspects of the present invention generally can have a peakmolecular weight (Mp), for instance, in a range from about 50,000 toabout 130,000, from about 52,000 to about 132,000, from about 55,000 toabout 130,000, or from 55,000 to about 120,000 g/mol. In some aspects,the ethylene polymer can have a Mp in a range from about 65,000 to about120,000, from about 60,000 to about 130,000, from about 60,000 to about120,000, or from about 65,000 to about 115,000 g/mol, and the like.

In an aspect, ethylene polymers described herein can have a ratio ofMw/Mn, or the polydispersity index, in a range from about 5 to about 22,from about 5 to about 20, from about 6 to about 20, from about 6 toabout 18, from about 6 to about 16, or from about 6 to about 14. Inanother aspect, ethylene polymers described herein can have a Mw/Mn in arange from about 7 to about 22, from about 7 to about 20, from about 7to about 18, or from about 7 to about 15.

In an aspect, ethylene polymers described herein can have a ratio ofMz/Mw in a range from about 3.5 to about 8.5, from about 3.5 to about 8,from about 4 to about 8.5, or from about 4 to about 8. In anotheraspect, ethylene polymers described herein can have a Mz/Mw in a rangefrom about 3.5 to about 7.5, from about 4 to about 7.5, or from about 4to about 7.

In an aspect, ethylene polymers described herein can have aweight-average molecular weight (Mw) in a range from about 275,000 toabout 800,000, from about 300,000 to about 750,000, from about 325,000to about 650,000, from about 325,000 to about 600,000, or from about325,000 to about 575,000 g/mol. In another aspect, ethylene polymersdescribed herein can have a Mw in a range from about 325,000 to about550,000, from about 350,000 to about 750,000, from about 375,000 toabout 650,000, or from about 375,000 to about 550,000 g/mol.

In an aspect, ethylene polymers described herein can have aviscosity-average molecular weight (Mv) in a range from about 225,000 toabout 600,000, from about 225,000 to about 550,000, from about 250,000to about 600,000, from about 250,000 to about 550,000, or from about250,000 to about 450,000 g/mol.

In an aspect, ethylene polymers described herein can have anumber-average molecular weight (Mn) in a range from about 20,000 toabout 60,000, from about 20,000 to about 55,000, or from about 25,000 toabout 60,000 g/mol. In another aspect, ethylene polymers describedherein can have a Mn in a range from about 25,000 to about 55,000, fromabout 30,000 to about 60,000, from about 30,000 to about 55,000, or fromabout 30,000 to about 50,000 g/mol.

In an aspect, ethylene polymers described herein can have a z-averagemolecular weight (Mz) in a range from about 1,500,000 to about10,000,000, from about 1,750,000 to about 7,500,000, or from about1,750,000 to about 5,000,000 g/mol. In another aspect, ethylene polymersdescribed herein can have a Mz in a range from about 1,750,000 to about4,000,000, or from about 2,000,000 to about 4,000,000 g/mol.

In an aspect, ethylene polymers described herein can have a CY-aparameter at 190° C. in a range from about 0.06 to about 0.45, fromabout 0.08 to about 0.4, from about 0.08 to about 0.35, or from about0.1 to about 0.35. Additionally or alternatively, ethylene polymersdescribed herein can have a zero-shear viscosity at 190° C. of greaterthan or equal to about 5×10⁵, greater than or equal to about 7.5×10⁵,greater than or equal to about 1×10⁶, in a range in a range from about7.5×10⁵ to about 1×10⁹, or in a range from about 1×10⁶ to about 1×10⁹Pa-sec. Additionally or alternatively, ethylene polymers describedherein can have a viscosity at 100 sec⁻¹ (eta @ 100 or η @100) at 190°C. in a range from about 1800 to about 4000, from about 2000 to about4000, from about 1800 to about 3800, from about 2000 to about 3800, fromabout 1800 to about 3500, or from about 2000 to about 3500 Pa-sec. Theserheological parameters were determined at 190° C. using theCarreau-Yasuda (CY) empirical model with creep adjustment, as describedherein, with the exception of Example 1, where the parameters weredetermined without creep adjustment.

Aspects of this invention also are directed to the performance of theethylene polymer (e.g., an ethylene/1-hexene copolymer) onrepresentative blow molding equipment, as described herein below.Ethylene polymers described herein can have a hang time in a range fromabout 10 to about 40, from about 10 to about 35, from about 12 to about40, from about 14 to about 40, from about 14 to about 35, from about 12to about 35, or from about 14 to about 30 sec. Additionally oralternatively, ethylene polymers described herein can have a part weightin a range from about 1700 to about 3000, from about 1800 to about 2600,from about 1700 to about 2600, from about 1700 to about 2500, or fromabout 1800 to about 2500 g. Additionally or alternatively, ethylenepolymers described herein can have a layflat in a range from about 8 toabout 12, from about 8 to about 11, from about 9 to about 12, or fromabout 9 to about 11 inches.

Ethylene polymers consistent with certain aspects of the invention oftencan have a bimodal molecular weight distribution (as determined usinggel permeation chromatography (GPC) or other suitable analyticaltechnique). Often, in a bimodal molecular weight distribution, there isa valley between the peaks, and the peaks can be separated ordeconvoluted. Typically, a bimodal molecular weight distribution can becharacterized as having an identifiable high molecular weight component(or distribution) and an identifiable low molecular weight component (ordistribution). Illustrative unimodal MWD curves and bimodal MWD curvesare shown in U.S. Pat. No. 8,383,754, incorporated herein by referencein its entirety.

In an aspect, the ethylene polymer described herein can be a reactorproduct (e.g., a single reactor product), for example, not apost-reactor blend of two polymers, for instance, having differentmolecular weight characteristics. As one of skill in the art wouldreadily recognize, physical blends of two different polymer resins canbe made, but this necessitates additional processing and complexity notrequired for a reactor product.

Polymers of ethylene, whether homopolymers, copolymers, and so forth,can be formed into various articles of manufacture. Articles which cancomprise polymers of this invention include, but are not limited to, anagricultural film, an automobile part, a bottle, a container forchemicals, a drum, a fiber or fabric, a food packaging film orcontainer, a food service article, a fuel tank, a geomembrane, ahousehold container, a liner, a molded product, a medical device ormaterial, an outdoor storage product, outdoor play equipment, a pipe, asheet or tape, a toy, or a traffic barrier, and the like. Variousprocesses can be employed to form these articles. Non-limiting examplesof these processes include injection molding, blow molding, rotationalmolding, film extrusion, sheet extrusion, profile extrusion,thermoforming, and the like. Additionally, additives and modifiers areoften added to these polymers in order to provide beneficial polymerprocessing or end-use product attributes. Such processes and materialsare described in Modern Plastics Encyclopedia, Mid-November 1995 Issue,Vol. 72, No. 12; and Film Extrusion Manual—Process, Materials,Properties, TAPPI Press, 1992; the disclosures of which are incorporatedherein by reference in their entirety. In some aspects of thisinvention, an article of manufacture can comprise any of ethylenepolymers described herein, and the article of manufacture can be a blowmolded article.

Applicants also contemplate a method for forming or preparing an articleof manufacture comprising a polymer produced by any of thepolymerization processes disclosed herein. For instance, a method cancomprise (i) contacting a catalyst composition with an olefin monomerand an optional olefin comonomer under polymerization conditions in apolymerization reactor system to produce an olefin polymer, wherein thecatalyst composition can comprise catalyst component I, catalystcomponent II, an activator (e.g., an activator-support comprising asolid oxide treated with an electron-withdrawing anion), and an optionalco-catalyst (e.g., an organoaluminum compound); and (ii) forming anarticle of manufacture comprising the olefin polymer. The forming stepcan comprise blending, melt processing, extruding, molding (e.g., blowmolding), or thermoforming, and the like, including combinationsthereof.

EXAMPLES

The invention is further illustrated by the following examples, whichare not to be construed in any way as imposing limitations to the scopeof this invention. Various other aspects, embodiments, modifications,and equivalents thereof which, after reading the description herein, maysuggest themselves to one of ordinary skill in the art without departingfrom the spirit of the present invention or the scope of the appendedclaims.

Melt index (MI, g/10 min) was determined in accordance with ASTM D1238at 190° C. with a 2,160 gram weight, and high load melt index (HLMI,g/10 min) was determined in accordance with ASTM D1238 at 190° C. with a21,600 gram weight. Polymer density was determined in grams per cubiccentimeter (g/cm³) on a compression molded sample, cooled at about 15°C. per hour, and conditioned for about 40 hours at room temperature inaccordance with ASTM D1505 and ASTM D4703. ESCR was determined inaccordance with ASTM D1693, condition B, with 10% igepal. Tensile Impactwas determined in accordance with ASTM D1822, and Charpy Impact wasdetermined in accordance with ISO 179-1.

Molecular weights and molecular weight distributions were obtained usinga PL-GPC 220 (Polymer Labs, an Agilent Company) system equipped with aIR4 detector (Polymer Char, Spain) and three Styragel HMW-6E GPC columns(Waters, Mass.) running at 145° C. The flow rate of the mobile phase1,2,4-trichlorobenzene (TCB) containing 0.5 g/L2,6-di-t-butyl-4-methylphenol (BHT) was set at 1 mL/min, and polymersolution concentrations were in the range of 1.0-1.5 mg/mL, depending onthe molecular weight. Sample preparation was conducted at 150° C. fornominally 4 hr with occasional and gentle agitation, before thesolutions were transferred to sample vials for injection. An injectionvolume of about 200 μL was used. The integral calibration method wasused to deduce molecular weights and molecular weight distributionsusing a Chevron Phillips Chemical Company's HDPE polyethylene resin,MARLEX® BHB5003, as the broad standard. The integral table of the broadstandard was pre-determined in a separate experiment with SEC-MALS. Mnis the number-average molecular weight, Mw is the weight-averagemolecular weight, Mz is the z-average molecular weight, Mv is theviscosity-average molecular weight, and Mp is the peak molecular weight(location, in molecular weight, of the highest point of the molecularweight distribution curve).

Melt rheological characterizations were performed as follows.Small-strain (10%) oscillatory shear measurements were performed on aRheometrics Scientific, Inc. ARES rheometer using parallel-plategeometry. All rheological tests were performed at 190° C. The complexviscosity |η*| versus frequency (ω) data were then curve fitted usingthe modified three parameter Carreau-Yasuda (CY) empirical model toobtain the zero shear viscosity—η₀, characteristic viscous relaxationtime—τ_(η), and the breadth parameter—α. The simplified Carreau-Yasuda(CY) empirical model is as follows.

${{{\eta^{*}(\omega)}} = \frac{\eta_{0}}{\left\lbrack {1 + \left( {\tau_{\eta}\omega} \right)^{a}} \right\}^{{({1 - n})}/a}}},$wherein: |η*(ω)|=magnitude of complex shear viscosity;

-   -   η₀=zero shear viscosity;    -   τ_(η)=viscous relaxation time (Tau(η));    -   a=“breadth” parameter (CY-a parameter);    -   n=fixes the final power law slope, fixed at 2/11; and    -   ω=angular frequency of oscillatory shearing deformation.

Details of the significance and interpretation of the CY model andderived parameters may be found in: C. A. Hieber and H. H. Chiang,Rheol. Acta, 28, 321 (1989); C. A. Hieber and H. H. Chiang, Polym. Eng.Sci., 32, 931 (1992); and R. B. Bird, R. C. Armstrong and O. Hasseger,Dynamics of Polymeric Liquids, Volume 1, Fluid Mechanics, 2nd Edition,John Wiley & Sons (1987); each of which is incorporated herein byreference in its entirety.

A creep adjustment was used to extend the low frequency range ofrheological characterization to 10⁻⁴ sec⁻¹. In the creep test, aconstant shear stress σ₀ was applied to the specimen and the shearstrain γ was recorded as a function of creep time t. Although thetime-dependent data generated by the creep and creep recovery tests lookdifferent from the frequency-dependent data measured in the dynamicfrequency sweep test, as long as the measurements are performed in thelinear viscoelastic regime, these two experimental data sets contain thesame rheological information, so that the time-dependent creepcompliance data can be transformed into the frequency-dependent dynamicdata, and thus the long time creep measurement can supplement the lowfrequency data of the dynamic frequency sweep measurement.

The generalized Voigt model was used for modeling the time-dependentcreep compliance J(t)=γ(t)/σ₀ in terms of a discrete spectrum J_(k) ofretardation times τ_(k) and zero shear rate viscosity η₀,

${J(t)} = {{\sum\limits_{k = 1}^{N}\;{J_{k}\left( {1 - {\mathbb{e}}^{{- t}/\tau_{k}}} \right)}} + {\frac{t}{\eta_{0}}.}}$

If the discrete retardation spectrum accurately describes the compliancedata, the theory of linear viscoelasticity permits a quantitativedescription of other types of experimental data, for example, thestorage and the loss compliance calculated as

${{J^{\prime}(\omega)} = {\sum\limits_{k = 1}^{N}\;{J_{k}\frac{1}{1 + {\omega^{2}\tau_{k}^{2}}}}}},\mspace{31mu}{{J^{''}(\omega)} = {\frac{1}{{\omega\eta}_{0}} + {\sum\limits_{k = 1}^{N}\;{J_{k}{\frac{{\omega\tau}_{k}}{1 + {\omega^{2}\tau_{k}^{2}}}.}}}}}$

From the relationship between the complex modulus and the complexcompliance, the storage and loss modulus of dynamic frequency sweep datacan be obtained as

${{G^{\prime}(\omega)} = \frac{J^{\prime}(\omega)}{\left\lbrack {J^{\prime}(\omega)} \right\rbrack^{2} + \left\lbrack {J^{''}(\omega)} \right\rbrack^{2}}},{{G^{\prime}(\omega)} = {\frac{J^{''}(\omega)}{\left\lbrack {J^{\prime}(\omega)} \right\rbrack^{2} + \left\lbrack {J^{''}(\omega)} \right\rbrack^{2}}.}}$

As a simple numerical approach to obtain the discrete spectrum ofretardation times, the Microsoft Excel Solver tool can be used byminimizing the following objective function O.

$O = {\sum\limits_{i = 1}^{N}\;{\frac{\left\lbrack {{J_{\exp}\left( t_{i} \right)} - {J_{model}\left( t_{i} \right)}} \right\rbrack^{2}}{\left\lbrack {J_{\exp}\left( t_{i} \right)} \right\rbrack^{2}}.}}$

For reliable conversion of the time-dependent creep data into thefrequency-dependent dynamic data, the frequency range needs to belimited by the testing time of the creep measurement. If it is possibleto obtain precise experimental data over the entire range of creep timeuntil the creep compliance reaches the steady state, the exact functionof retardation spectra over the entire range of time scale also can becalculated. However, it is often not practical to obtain such data forhigh molecular weight polymers, which have very long relaxation times.The creep data only contain information within a limited range of time,so that the frequency range is limited by the duration time t_(N) of thecreep test, i.e., valid information for frequencies is in the range ofω>t_(N) ⁻¹, and the extrapolated data outside this frequency range canbe influenced by artifacts of the fittings.

For the rheological measurements involving a creep adjustment, thepolymer samples were compression molded at 182° C. for a total of 3 min.The samples were allowed to melt at a relatively low pressure for 1 minand then subjected to a high molding pressure for an additional 2 min.The molded samples were then quenched in a room temperature press, andthen 25.4 mm diameter disks were stamped out of the molded slabs for themeasurement in the rotational rheometer. The measurements were performedin parallel plates of 25 mm diameter at 190° C. using acontrolled-stress rheometer equipped with an air bearing system (PhysicaMCR-500, Anton Paar). The test chamber of the rheometer was purged withnitrogen to minimize oxidative degradation. After thermal equilibration,the specimens were squeezed between the plates to a 1.6 mm thickness,and the excess was trimmed. A total of 8 min elapsed between the timethe sample was inserted and the time the test was started. For thedynamic frequency sweep measurement, small-strain (1˜10%) oscillatoryshear in the linear viscoelastic regime was applied at angularfrequencies from 0.0316 to 316 sec⁻¹. The creep test was performed for10,200 sec (170 min) to limit the overall testing time within 4 hr,since sample throughput and thermal stability were concerns. Byconverting the time dependent creep data to frequency dependent dynamicdata, the low frequency range was extended down to 10⁻⁴ rad/sec, twoorders of magnitude lower than the frequency range of the dynamic test.The complex viscosity (|η*|) versus frequency (ω) data were curve fittedusing the Carreau-Yasuda model.

One of the major concerns in performing the creep test, and indeed anylong time scale measurement, was that the sample does not appreciablychange during the measurement, which may take several hours to perform.If a polymer sample is heated for long time period without properthermal stabilization (e.g., antioxidants), changes in the polymer canoccur that can have a significant effect on the rheological behavior ofthe polymer and its characterization. Polymers which are being testedshould have thermal stability for at least 4-5 hr at 190° C. undernitrogen; for example, ethylene polymers containing at least 0.4 wt. %of antioxidants were found to be stable enough to obtain valid creepadjustment data.

For the rheological measurement in the parallel plates, the specimen wassqueezed between the plates to a 1.6 mm thickness, and then the excesswas trimmed. When the sample was trimmed with large forces on onedirection, some residual stress was generated to cause the strain todrift. Therefore, performing the creep test right after sample trimmingshould be avoided, because the residual stress can affect the subsequentcreep measurement, particularly for the highly viscoelastic resinshaving long relaxation times. If the applied stress of the creep test isnot large enough, the resulting strain can be so small that the creepresults can be influenced by the artifact of the strain drifting. Inorder to minimize this effect, samples were trimmed as gently aspossible, and the creep test was conducted after 2000 sec of waitingtime, in order to allow relaxation of any residual stress.

The appropriate magnitude of applied stress σ₀ is important for reliablecreep data. The stress σ₀ must be sufficiently small such that thestrain will stay within the linear viscoelastic regime, and it must besufficiently large such that the strain signal is strong enough toprovide satisfactory resolution of data for good precision. Although notlimited thereto, a suitable applied stress was equal to the complexmodulus |G*| at a frequency of 0.01 rad/sec multiplied by 0.04.

SEC-MALS combines the methods of size exclusion chromatography (SEC)with multi-angle light scattering (MALS) detection. A DAWN EOS 18-anglelight scattering photometer (Wyatt Technology, Santa Barbara, Calif.)was attached to a PL-210 SEC system (Polymer Labs, now Agilent) or aWaters 150 CV Plus system (Milford, Mass.) through a hot transfer line,thermally controlled at the same temperature as the SEC columns and itsdifferential refractive index (DRI) detector (145° C.). At a flow ratesetting of 0.7 mL/min, the mobile phase, 1,2,4-trichlorobenzene (TCB),was eluted through three, 7.5 mm×300 mm, 20 μm Mixed A-LS columns(Polymer Labs, now Agilent). Polyethylene (PE) solutions withconcentrations of ˜1.2 mg/mL, depending on samples, were prepared at150° C. for 4 hr before being transferred to the SEC injection vialssitting in a carousel heated at 145° C. For polymers of higher molecularweight, longer heating times were necessary in order to obtain truehomogeneous solutions. In addition to acquiring a concentrationchromatogram, seventeen light-scattering chromatograms at differentangles were also acquired for each injection using Wyatt's Astra®software. At each chromatographic slice, both the absolute molecularweight (M) and root mean square (RMS) radius, also known as radius ofgyration (Rg) were obtained from a Debye plot's intercept and slope,respectively. Methods for this process are detailed in Wyatt, P. J.,Anal. Chim. Acta, 272, 1 (1993), which is incorporated herein byreference in its entirety.

The Zimm-Stockmayer approach was used to determine the amount of LCB.Since SEC-MALS measures M and Rg at each slice of a chromatogramsimultaneously, the branching indices, g_(M), as a function of M couldbe determined at each slice directly by determining the ratio of themean square Rg of branched molecules to that of linear ones, at the sameM, as shown in following equation (subscripts br and lin representbranched and linear polymers, respectively).

$g_{M} = {\frac{\left\langle R_{g} \right\rangle_{br}^{2}}{\left\langle R_{g} \right\rangle_{lin}^{2}}.}$

At a given g_(M), the weight-averaged number of LCB per molecule(B_(3w)) was computed using Zimm-Stockmayer's equation, shown in theequation below, where the branches were assumed to be trifunctional, orY-shaped.

$g_{M} = {\frac{6}{B_{3\; w}}{\left\{ {{\frac{1}{2}\left( \frac{2 + B_{3\; w}}{B_{3\; w}} \right)^{1/2}{\ln\left\lbrack \frac{\left( {2 + B_{3\; w}} \right)^{1/2} + \left( B_{3\; w} \right)^{1/2}}{\left( {2 + B_{3\; w}} \right)^{1/2} - \left( B_{3\; w} \right)^{1/2}} \right\rbrack}} - 1} \right\}.}}$

LCB frequency (LCB_(Mi)), the number of LCB per 1000 C, of the i^(th)slice was then computed straightforwardly using the following equation(M_(i) is the MW of the i^(th) slice):LCB_(Mi)=1000*14*B _(3w) /M _(i).

The LCB distribution (LCBD) across the molecular weight distribution(MWD) was thus established for a full polymer.

Short chain branch (SCB) content and short chain branching distribution(SCBD) across the molecular weight distribution can be determined via anIR5-detected GPC system (IR5-GPC), wherein the GPC system is a PL220GPC/SEC system (Polymer Labs, an Agilent company) equipped with threeStyragel HMW-6E columns (Waters, Mass.) for polymer separation. Athermoelectric-cooled IR5 MCT detector (IR5) (Polymer Char, Spain) isconnected to the GPC columns via a hot-transfer line. Chromatographicdata are obtained from two output ports of the IR5 detector. First, theanalog signal goes from the analog output port to a digitizer beforeconnecting to Computer “A” for molecular weight determinations via theCirrus software (Polymer Labs, now an Agilent Company) and the integralcalibration method using a broad MWD HDPE Marlex™ BHB5003 resin (ChevronPhillips Chemical) as the broad molecular weight standard. The digitalsignals, on the other hand, go via a USB cable directly to Computer “B”where they are collected by a LabView data collection software providedby Polymer Char. Chromatographic conditions are set as follows: columnoven temperature of 145° C.; flowrate of 1 mL/min; injection volume of0.4 mL; and polymer concentration of about 2 mg/mL, depending on samplemolecular weight. The temperatures for both the hot-transfer line andIR5 detector sample cell are set at 150° C., while the temperature ofthe electronics of the IR5 detector is set at 60° C. Short chainbranching content is determined via an in-house method using theintensity ratio of CH₃ (I_(CH3)) to CH₂ (I_(CH2)) coupled with acalibration curve. The calibration curve is a plot of SCB content(X_(SCB)) as a function of the intensity ratio of I_(CH3)/I_(CH2). Toobtain a calibration curve, a group of polyethylene resins (no less than5) of SCB level ranging from zero to ca. 32 SCB/1,000 total carbons (SCBStandards) is used. All these SCB Standards have known SCB levels andflat SCBD profiles pre-determined separately by NMR and thesolvent-gradient fractionation coupled with NMR (SGF-NMR) methods. UsingSCB calibration curves thus established, profiles of short chainbranching distribution across the molecular weight distribution areobtained for resins fractionated by the IR5-GPC system under exactly thesame chromatographic conditions as for these SCB standards. Arelationship between the intensity ratio and the elution volume isconverted into SCB distribution as a function of MWD using apredetermined SCB calibration curve (i.e., intensity ratio ofI_(CH3)/I_(CH2) VS. SCB content) and MW calibration curve (i.e.,molecular weight vs. elution time) to convert the intensity ratio ofI_(CH3)/I_(CH2) and the elution time into SCB content and the molecularweight, respectively.

Blow molding evaluations of Examples 1-9 were performed on a KautexKB-25 blow molding machine with the following specifications. Theseparticular equipment and processing conditions were chosen because theblow molding performance and properties so obtained are typicallyrepresentative of those obtained from larger, commercial scale blowmolding operations. The extruder screw diameter was 80 mm, the L/D Ratiowas 20:1, the drive motor was a 60 HP DC drive, and the maximumplasticizing capacity was about 330 lb polyethylene per hr. The extruderwas equipped with a dynicso pressure indicator, three heating zones withair cooling, and a liquid cooled, grooved liner in the feed zone forprocessing high molecular weight polyethylene pellet and powder resins.

The accumulator head (FIFO Design) had a maximum shot capacity of 8.5lb, a die bushing diameter maximum and minimum of 8″ and 2″(respectively), where 2″ thru 3½″ is converging, and 4″ thru 8″ isdiverging. The blow molding machine was also equipped with a 100 pointHunkar programmer.

For Examples 1-9, all extruder and head zones were set at 405° F. Themold was a 9-gallon bottle (Fremont Plastics Mold), and 4.5″ divergingdie head with a 30 degree land angle was used. A constant extrusionpressure was used. The mold temperature was 50-60° F. The timer settingswere a 0.5 sec blow delay, a 0 sec preblow, and a 0 sec mold closedelay. Air pressure was 90 psig. The minimum wall thickness of the partswas in the 45-50 mil range, and the die gap was 0.196″. Parts wereproduced at an extruder speed of 30 RPM and a blow time of 90 sec.

The weight of the bottle produced (part weight) was recorded, and thewidth of the flashing at the bottom of the bottle (layflat bottom) wasmeasured. Die swell (parison size versus die size) and weight swell(change in part weight at constant die gap and parison speed) weredetermined. The melt strengths of the polymers were compared via a hangtime test using a 0.089″ die gap and 20 RPM extruder speed. A parisonwas extruded and allowed to hang; the extruder speed was turned to zerowhile the parison was hanging. The time from the end of the shot to thetime the parison tore away from the bushing was recorded as the hangtime.

Fluorided silica-coated alumina activator-supports used in Examples 2-8were prepared as follows. Bohemite was obtained from W.R. Grace &Company under the designation “Alumina A” and having a surface area ofabout 300 m²/g, a pore volume of about 1.3 mL/g, and an average particlesize of about 100 microns. The alumina was first calcined in dry air atabout 600° C. for approximately 6 hours, cooled to ambient temperature,and then contacted with tetraethylorthosilicate in isopropanol to equal25 wt. % SiO₂. After drying, the silica-coated alumina was calcined at600° C. for 3 hours. Fluorided silica-coated alumina (7 wt. % F) wasprepared by impregnating the calcined silica-coated alumina with anammonium bifluoride solution in methanol, drying, and then calcining for3 hours at 600° C. in dry air. Afterward, the fluorided silica-coatedalumina was collected and stored under dry nitrogen, and was usedwithout exposure to the atmosphere.

Pilot plant polymerizations were conducted in a 23-gallon slurry loopreactor at a production rate of approximately 33 pounds of polymer perhour. Polymerization runs were carried out under continuous particleform process conditions in a loop reactor (also referred to as a slurryprocess) by contacting a dual metallocene solution in isobutane, anorganoaluminum solution (triisobutylaluminum, TIBA), and anactivator-support (fluorided silica-coated alumina) in a 2 L stirredautoclave with continuous output to the loop reactor. The TIBA and dualmetallocene solutions were fed as separate streams into a tee upstreamof the autoclave where they contacted each other. The activator-supportwas flushed with isobutane into a tee between the aforementioned tee andthe autoclave, contacting the organoaluminum/metallocene mixture justbefore entering the autoclave. The isobutane flush used to transport theactivator-support into the autoclave was set at a rate that would resultin a residence time of approximately 25 minutes in the autoclave. Thetotal flow from the autoclave then entered the loop reactor.

Ethylene used was polymerization grade ethylene which was purifiedthrough a column of alumina (activated at 250° C. in nitrogen). 1-Hexenewas polymerization grade 1-hexene (obtained from Chevron PhillipsChemical Company) which was purified by nitrogen purging and storageover 13-X molecular sieve activated at 250° C. (482° F.) in nitrogen.The loop reactor was a liquid full, 15.2 cm diameter, loop reactor,having a volume of 23 gallons (87 liters). Liquid isobutane was used asthe diluent. Hydrogen was added at about 1-2 mlb/hr to regulate themolecular weight and/or HLMI of the polymer product. The isobutane waspolymerization grade isobutane (obtained from Chevron Phillips ChemicalCompany) that was further purified by distillation and subsequentlypassed through a column of alumina (activated at 250° C. in nitrogen).

Reactor conditions included a reactor pressure around 590 psig, a mol %ethylene of 11-13% (based on isobutane diluent), and a polymerizationtemperature of 90-91° C. Also, the reactor was operated to have aresidence time of about 1.25 hr. Metallocene concentrations in thereactor were within a range of about 1.4 to 2 parts per million (ppm) byweight of the diluent in the polymerization reactor. Theactivator-support (fluorided silica-coated alumina) was fed to thereactor at the rate of approximately 0.2-0.3 lb per hour. Polymer wasremoved from the reactor at the rate of about 33 lb/hr and recovered ina flash chamber. A Vulcan dryer was used to dry the polymer undernitrogen at about 60-80° C.

Co-catalyst TIBA was obtained as a one molar solution in heptane, butwas further diluted to 1 weight percent. The co-catalyst was added in aconcentration in a range of from about 140 to 175 ppm based on theweight of the diluent in the polymerization reactor. The structures forMET 1 and MET 2, used in Examples 2-8, are shown below:

Table I summarizes certain information relating to the polymerizationexperiments of Examples 2-8.

Examples 1-9

Example 1 was a broad monomodal copolymer resin, having a nominal 5-6HLMI and 0.954 density, produced using a chromium-based catalyst system(Chevron-Phillips Chemical Company LP). Example 9 was a broad monomodalcopolymer resin, having a nominal 8-10 HLMI and 0.948 density, producedusing a chromium-based catalyst system (Chevron-Phillips ChemicalCompany LP). Each of Examples 2-8 utilized a dual catalyst systemcontaining MET 1 and MET 2 at the relative amounts listed in Table I.

FIGS. 1-2 illustrate the bimodal molecular weight distributions (amountof polymer versus the logarithm of molecular weight) of the polymers ofExamples 2-8, and Table II summarizes certain molecular weightcharacteristics of the polymers of Examples 1-8. The polymers ofExamples 2-8 had Mp values ranging from about 68,000 to 95,000 g/mol, Mwvalues ranging from about 370,000 to about 550,000 g/mol, and Mn valuesranging from about 30,000 to about 50,000 g/mol. In contrast, theunimodal polymer of Example 1 had lower Mw and Mn values.

FIGS. 3-4 illustrate the dynamic rheology properties at 190° C. for thepolymers of Examples 1 and 3-8, and Table III summarizes certainrheological characteristics of the polymers of Examples 1-8.Surprisingly, metallocene-based polymers (Examples 2-8) were producedhaving roughly equivalent processability to that of a chromium-basedpolymer (Example 1), and with equivalent or superior melt strength(e.g., as reflected in the zero-shear viscosity). The Carreau-Yasuda(CY) model was used for Example 1, while the CY model with creepadjustment was used for Examples 2-8.

FIG. 5 illustrates the low levels of LCB of the polymers consistent withaspects of this invention. The radius of gyration versus the logarithmof the molecular weight for a linear standard and the polymers ofExamples 4, 5, and 7, with data from SEC-MALS, is provided in FIG. 5.These polymers were substantially linear with minimal amounts of LCB,e.g., less than about 0.01 LCB, or less than about 0.008 LCB, etc., per1000 total carbon atoms in the 500,000 to 5,000,000 g/mol molecularweight range, or in the 500,000 to 2,000,000 g/mol molecular weightrange, of the polymer.

Table IV summarizes certain polymer and mechanical/performanceproperties of Examples 1-9, while Table V summarizes the blow moldingperformance of Examples 1-9. The polymers of Examples 2-8 had densitiesranging from about 0.950 to 0.958 g/cm³ and HLMI's ranging from about 3to about 10 g/10 min; these characteristics were similar to those ofExamples 1 and 9. Unexpectedly, however, the ESCR and impact (Charpy andTensile) properties of Examples 2-8 were far superior to those ofExamples 1 and 9; for instance, the ESCR performance was at least 10times better. Hence, the polymers described herein can provide improvedtoughness, impact strength, and ESCR at an equivalent (or higher)density and/or HLMI, as compared to chromium-based resins.

The test results in Table V indicate that the polymers of Examples 2-8,unexpectedly, processed similarly to those of the chromium-basedpolymers of Examples 1 and 9, for example, with similar hang time, partweight, and layflat bottom results in representative blow moldingexperiments. Using Example 1 as a benchmark, the polymers of Examples2-8 also had surprisingly similar die swell and weight swell. Theseresults confirm the chromium-like processability of the polymers ofExamples 2-8 under commercial blow molding conditions.

TABLE I Examples 2-8 - Polymerization Data and Polymer HLMI and Density1-hexene MET 1/MET 2 H₂ Feed C₂H₄ (mlb/lb TIBA HLMI Density Example(ppm) (mlb/hr) (mol %) C₂H₄) (ppm) (g/10 min) (g/cc) 2 0.68/1.29 1.7512.34 1.8 154 3.35 0.9546 3 0.77/1.23 1.75 12.17 2.3 153 4.73 0.9566 40.68/1.09 1.75 11.19 3.7 146 9.70 0.9548 5 0.54/0.99 1.75 12.06 3.5 1426.78 0.9542 6 0.56/0.93 1 12.06 2.5 153 3.36 0.9521 7 0.71/0.97 1 11.863.5 170 4.77 0.9534 8 0.65/0.79 1 11.38 3.8 160 6.58 0.9528

TABLE II Examples 1-8 - Molecular Weight Characterization (g/mol)Example Mn/1000 Mw/1000 Mz/1000 Mv/1000 Mp/1000 Mw/Mn Mz/Mw IB Ivc 119.25 299.6 1945 217.1 84.3 15.56 6.49 1.729 2.96 2 38.07 539.2 2582384.7 69.0 14.16 4.79 1.537 4.48 3 35.08 472.0 2496 332.3 70.8 13.455.29 1.481 4.03 4 33.03 377.3 2119 265.6 69.0 11.42 5.62 1.385 3.42 534.44 421.1 2241 297.7 70.8 12.23 5.32 1.409 3.72 6 47.41 512.4 2754363.3 91.7 10.81 5.37 1.325 4.30 7 48.31 441.9 2646 310.1 94.1 9.15 5.991.274 3.83 8 46.61 424.8 2781 294.4 91.7 9.11 6.55 1.240 3.69

TABLE III Examples 1-8 - Rheological Characterization at 190° C. Zeroshear Tau(η) CY-a η @ 0.1 Tan d @ 0.1 η @ 100 Tan d @ 100 Example(Pa-sec) (sec) parameter (Pa-sec) (degrees) (Pa-sec) (degrees) 11.82E+06 7.53E+00 0.1927 1.07E+05 1.3860 2.83E+03 0.6353 2 4.68E+066.91E+01 0.4159 4.65E+05 0.8136 3.22E+03 0.3284 3 3.67E+06 6.06E+010.3710 3.37E+05 0.8789 2.71E+03 0.3475 4 2.78E+06 4.36E+01 0.26861.73E+05 1.0350 2.15E+03 0.4323 5 3.95E+06 6.61E+01 0.3036 2.52E+050.9294 2.47E+03 0.3864 6 2.33E+07 3.35E+02 0.2154 3.05E+05 0.83563.14E+03 0.4331 7 1.56E+07 2.15E+02 0.1992 2.13E+05 0.9089 2.62E+030.4714 8 8.67E+07 8.21E+02 0.1326 1.53E+05 0.9233 2.38E+03 0.5725

TABLE IV Examples 1-9 - HLMI, Density, and Mechanical/PerformanceProperties Tensile Density HLMI Charpy Impact ESCR (condition Example(g/cc) (g/10 min) (kJ/m²) (kJ/m²) B, 10%, hr) 1 0.9547 6.28 24.65 420102 2 0.9546 3.35 61.02 >733 >1000 3 0.9566 4.73 51.49 >733 >1000 40.9548 9.70 33.27 505 >1000 5 0.9542 6.78 37.84 691 >1000 6 0.9521 3.3659.13 >733 >1000 7 0.9534 4.77 48.44 633 >1000 8 0.9528 6.58 39.80578 >1000 9 0.9485 7.97 6.98 283 101

TABLE V Examples 1-9 - Blow Molding Performance Comparison Hang PartWeight Swell Layflat Die Swell Time Weight (Δ vs. Bottom (Δ vs. Example(sec) (g) Ex. 1, %) (in) Ex. 1, %) 1 21.5 2335 Base Line 10.5 Base Line2 28.0 1774 −0.24 9.5 −0.10 3 21.4 1789 −0.23 8.7 −0.17 4 10.9 2033−0.13 9.3 −0.11 5 17.4 1892 −0.19 8.8 −0.16 6 28.1 2298 −0.02 9.9 −0.067 16.4 2294 −0.02 9.9 −0.06 8 12.2 2427 0.04 10.6 0.01 9 27.8 2176 −0.079.9 −0.06

The invention is described above with reference to numerous aspects andembodiments, and specific examples. Many variations will suggestthemselves to those skilled in the art in light of the above detaileddescription. All such obvious variations are within the full intendedscope of the appended claims. Other embodiments of the invention caninclude, but are not limited to, the following (embodiments aredescribed as “comprising” but, alternatively, can “consist essentiallyof” or “consist of”):

Embodiment 1

An ethylene polymer having a density of greater than or equal to about0.945 g/cm³, a high load melt index (HLMI) in a range from about 1 toabout 25 g/10 min, a peak molecular weight (Mp) in a range from about52,000 to about 132,000 g/mol, and an environmental stress crackresistance (ESCR) of at least 250 hours.

Embodiment 2

An ethylene polymer having a density of greater than or equal to about0.945 g/cm³, a high load melt index (HLMI) in a range from about 1 toabout 25 g/10 min, a weight-average molecular weight (Mw) in a rangefrom about 275,000 to about 800,000 g/mol, a number-average molecularweight (Mn) in a range from about 20,000 to about 60,000 g/mol, and aratio of Mw/Mn in a range from about 5 to about 22.

Embodiment 3

The polymer defined in embodiment 1 or 2, wherein the ethylene polymerhas an environmental stress crack resistance (ESCR) in any rangedisclosed herein, e.g., at least 250 hours, at least 500 hours, at least1,000 hours, at least 1,500 hours, at least 2,000 hours, etc.

Embodiment 4

The polymer defined in any one of embodiments 1-3, wherein the ethylenepolymer has a melt index (MI) in any range disclosed herein, e.g., from0 to about 0.5, from 0 to about 0.25, from 0 to about 0.2, from 0 toabout 0.1 g/10 min, etc.

Embodiment 5

The polymer defined in any one of embodiments 1-4, wherein the ethylenepolymer has a HLMI in any range disclosed herein, e.g., from about 1 toabout 20, from about 2 to about 25, from about 2 to about 20, from about2 to about 15, from about 1 to about 10, from about 2 to about 10 g/10min, etc.

Embodiment 6

The polymer defined in any one of embodiments 1-5, wherein the ethylenepolymer has a density in any range disclosed herein, e.g., greater thanor equal to about 0.952, from about 0.945 to about 0.965, from about0.947 to about 0.962, from about 0.95 to about 0.965, from about 0.952to about 0.962, from about 0.952 to about 0.96 g/cm³, etc.

Embodiment 7

The polymer defined in any one of embodiments 1-6, wherein the ethylenepolymer has less than about 0.008 long chain branches (LCB) per 1000total carbon atoms, e.g., less than about 0.005 LCB, less than about0.003 LCB, etc.

Embodiment 8

The polymer defined in any one of embodiments 1-7, wherein the ethylenepolymer has a Tensile Impact in any range disclosed herein, e.g.,greater than or equal to about 400, greater than or equal to about 450,greater than or equal to about 500, greater than or equal to about 550,greater than or equal to about 600 kJ/m², etc.

Embodiment 9

The polymer defined in any one of embodiments 1-8, wherein the ethylenepolymer has a Charpy Impact in any range disclosed herein, e.g., fromabout 25 to about 75, from about 30 to about 75, from about 25 to about70, from about 30 to about 70, from about 30 to about 65, from about 28to about 68 kJ/m², etc.

Embodiment 10

The polymer defined in any one of embodiments 1-9, wherein the ethylenepolymer has a reverse comonomer distribution, e.g., the number of shortchain branches (SCB) per 1000 total carbon atoms of the polymer at Mw isgreater than at Mn, the number of short chain branches (SCB) per 1000total carbon atoms of the polymer at Mz is greater than at Mw, thenumber of SCB per 1000 total carbon atoms of the polymer at Mz isgreater than at Mn, the number of short chain branches (SCB) per 1000total carbon atoms of the polymer at a molecular weight of 10⁶ isgreater than at a molecular weight of 10⁵, etc.

Embodiment 11

The polymer defined in any one of embodiments 1-10, wherein the ethylenepolymer has a Mp in any range disclosed herein, e.g., from about 50,000to about 130,000, from about 52,000 to about 132,000, from about 65,000to about 120,000, from about 60,000 to about 130,000, from about 60,000to about 120,000, from about 65,000 to about 115,000 g/mol, etc.

Embodiment 12

The polymer defined in any one of embodiments 1-11, wherein the ethylenepolymer has a Mw in any range disclosed herein, e.g., from about 300,000to about 750,000, from about 325,000 to about 650,000, from about325,000 to about 600,000, from about 325,000 to about 575,000, fromabout 325,000 to about 550,000, from about 350,000 to about 750,000,from about 375,000 to about 650,000, from about 375,000 to about 550,000g/mol, etc.

Embodiment 13

The polymer defined in any one of embodiments 1-12, wherein the ethylenepolymer has a Mn in any range disclosed herein, e.g., from about 20,000to about 55,000, from about 25,000 to about 60,000, from about 25,000 toabout 55,000, from about 30,000 to about 60,000, from about 30,000 toabout 55,000, from about 30,000 to about 50,000 g/mol, etc.

Embodiment 14

The polymer defined in any one of embodiments 1-13, wherein the ethylenepolymer has a Mz in any range disclosed herein, e.g., from about1,500,000 to about 10,000,000, from about 1,750,000 to about 7,500,000,from about 1,750,000 to about 5,000,000, from about 1,750,000 to about4,000,000, from about 2,000,000 to about 4,000,000 g/mol, etc.

Embodiment 15

The polymer defined in any one of embodiments 1-14, wherein the ethylenepolymer has a ratio of Mw/Mn in any range disclosed herein, e.g., fromabout 5 to about 22, from about 5 to about 20, from about 6 to about 18,from about 7 to about 20, from about 7 to about 15, etc.

Embodiment 16

The polymer defined in any one of embodiments 1-15, wherein the ethylenepolymer has a ratio of Mz/Mw in any range disclosed herein, e.g., fromabout 3.5 to about 8.5, from about 4 to about 8, from about 4 to about7, etc.

Embodiment 17

The polymer defined in any one of embodiments 1-16, wherein the ethylenepolymer has a CY-a parameter in any range disclosed herein, e.g., fromabout 0.06 to about 0.45, from about 0.08 to about 0.4, from about 0.1to about 0.35, etc.

Embodiment 18

The polymer defined in any one of embodiments 1-17, wherein the ethylenepolymer has a zero-shear viscosity in any range disclosed herein, e.g.,greater than or equal to about 5×10⁵, greater than or equal to about7.5×10⁵, greater than or equal to about 1×10⁶, in a range from about1×10⁶ to about 1×10⁹ Pa-sec, etc.

Embodiment 19

The polymer defined in any one of embodiments 1-18, wherein the ethylenepolymer has a viscosity at 100 sec⁻¹ (eta @ 100 or η @ 100) in any rangedisclosed herein, e.g., from about 1800 to about 4000, from about 2000to about 4000, from about 1800 to about 3800, from about 2000 to about3800, from about 1800 to about 3500, from about 2000 to about 3500Pa-sec, etc.

Embodiment 20

The polymer defined in any one of embodiments 1-19, wherein the ethylenepolymer has a hang time in any range disclosed herein, e.g., from about10 to about 40, from about 10 to about 35, from about 12 to about 40,from about 14 to about 40, from about 14 to about 35, from about 12 toabout 35, from about 14 to about 30 sec, etc.

Embodiment 21

The polymer defined in any one of embodiments 1-20, wherein the ethylenepolymer has a part weight in any range disclosed herein, e.g., fromabout 1700 to about 3000, from about 1800 to about 2600, from about 1700to about 2600, from about 1700 to about 2500, from about 1800 to about2500 g, etc.

Embodiment 22

The polymer defined in any one of embodiments 1-21, wherein the ethylenepolymer has a layflat in any range disclosed herein, e.g., from about 8to about 12, from about 8 to about 11, from about 9 to about 12, fromabout 9 to about 11 inches, etc.

Embodiment 23

The polymer defined in any one of embodiments 1-22, wherein the ethylenepolymer has a bimodal molecular weight distribution.

Embodiment 24

The polymer defined in any one of embodiments 1-23, wherein the ethylenepolymer is a single reactor product, e.g., not a post-reactor blend oftwo polymers, for instance, having different molecular weightcharacteristics.

Embodiment 25

The polymer defined in any one of embodiments 1-24, wherein the ethylenepolymer is an ethylene/α-olefin copolymer.

Embodiment 26

The polymer defined in any one of embodiments 1-25, wherein the ethylenepolymer is an ethylene/1-butene copolymer, an ethylene/1-hexenecopolymer, or an ethylene/1-octene copolymer.

Embodiment 27

The polymer defined in any one of embodiments 1-26, wherein the ethylenepolymer is an ethylene/1-hexene copolymer.

Embodiment 28

An article comprising the ethylene polymer defined in any one ofembodiments 1-27.

Embodiment 29

An article comprising the ethylene polymer defined in any one ofembodiments 1-27, wherein the article is an agricultural film, anautomobile part, a bottle, a container for chemicals, a drum, a fiber orfabric, a food packaging film or container, a food service article, afuel tank, a geomembrane, a household container, a liner, a moldedproduct, a medical device or material, an outdoor storage product,outdoor play equipment, a pipe, a sheet or tape, a toy, or a trafficbarrier.

Embodiment 30

A catalyst composition comprising: catalyst component I comprising anyunbridged metallocene compound disclosed herein, catalyst component IIcomprising any bridged metallocene compound disclosed herein, anyactivator disclosed herein, and optionally, any co-catalyst disclosedherein.

Embodiment 31

The composition defined in embodiment 30, wherein catalyst component IIcomprises a bridged zirconium or hafnium based metallocene compound.

Embodiment 32

The composition defined in embodiment 30, wherein catalyst component IIcomprises a bridged zirconium or hafnium based metallocene compound withan alkenyl substituent.

Embodiment 33

The composition defined in embodiment 30, wherein catalyst component IIcomprises a bridged zirconium or hafnium based metallocene compound withan alkenyl substituent and a fluorenyl group.

Embodiment 34

The composition defined in embodiment 30, wherein catalyst component IIcomprises a bridged zirconium or hafnium based metallocene compound witha cyclopentadienyl group and a fluorenyl group, and with an alkenylsubstituent on the bridging group and/or on the cyclopentadienyl group.

Embodiment 35

The composition defined in embodiment 30, wherein catalyst component IIcomprises a bridged metallocene compound having an aryl groupsubstituent on the bridging group.

Embodiment 36

The composition defined in embodiment 30, wherein catalyst component IIcomprises a dinuclear bridged metallocene compound with an alkenyllinking group.

Embodiment 37

The composition defined in embodiment 30, wherein catalyst component IIcomprises a bridged metallocene compound having formula (II):

wherein M is any Group IV transition metal disclosed herein, Cp is anycyclopentadienyl, indenyl, or fluorenyl group disclosed herein, each Xindependently is any monoanionic ligand disclosed herein, R^(X) andR^(Y) independently are any substituent disclosed herein, and E is anybridging group disclosed herein.

Embodiment 38

The composition defined in any one of embodiments 30-37, whereincatalyst component I comprises an unbridged zirconium or hafnium basedmetallocene compound containing two cyclopentadienyl groups, two indenylgroups, or a cyclopentadienyl and an indenyl group.

Embodiment 39

The composition defined in any one of embodiments 30-37, whereincatalyst component I comprises an unbridged zirconium or hafnium basedmetallocene compound containing two cyclopentadienyl groups.

Embodiment 40

The composition defined in any one of embodiments 30-37, whereincatalyst component I comprises an unbridged zirconium or hafnium basedmetallocene compound containing two indenyl groups.

Embodiment 41

The composition defined in any one of embodiments 30-37, whereincatalyst component I comprises an unbridged zirconium or hafnium basedmetallocene compound containing a cyclopentadienyl and an indenyl group.

Embodiment 42

The composition defined in any one of embodiments 30-37, whereincatalyst component I comprises a dinuclear unbridged metallocenecompound with an alkenyl linking group.

Embodiment 43

The composition defined in any one of embodiments 30-37, whereincatalyst component I comprises an unbridged metallocene compound havingformula (I):

wherein M is any Group IV transition metal disclosed herein, Cp^(A) andCp^(B) independently are any cyclopentadienyl or indenyl group disclosedherein, and each X independently is any monoanionic ligand disclosedherein.

Embodiment 44

The composition defined in any one of embodiments 30-43, wherein theactivator comprises an activator-support, an aluminoxane compound, anorganoboron or organoborate compound, an ionizing ionic compound, or anycombination thereof.

Embodiment 45

The composition defined in any one of embodiments 30-44, wherein theactivator comprises an aluminoxane compound.

Embodiment 46

The composition defined in any one of embodiments 30-44, wherein theactivator comprises an organoboron or organoborate compound.

Embodiment 47

The composition defined in any one of embodiments 30-44, wherein theactivator comprises an ionizing ionic compound.

Embodiment 48

The composition defined in any one of embodiments 30-44, wherein theactivator comprises an activator-support, the activator-supportcomprising any solid oxide treated with any electron-withdrawing aniondisclosed herein.

Embodiment 49

The composition defined in any one of embodiments 30-44, wherein theactivator comprises fluorided alumina, chlorided alumina, bromidedalumina, sulfated alumina, fluorided silica-alumina, chloridedsilica-alumina, bromided silica-alumina, sulfated silica-alumina,fluorided silica-zirconia, chlorided silica-zirconia, bromidedsilica-zirconia, sulfated silica-zirconia, fluorided silica-titania,fluorided silica-coated alumina, sulfated silica-coated alumina,phosphated silica-coated alumina, or any combination thereof.

Embodiment 50

The composition defined in any one of embodiments 30-44, wherein theactivator comprises fluorided alumina, sulfated alumina, fluoridedsilica-alumina, sulfated silica-alumina, fluorided silica-coatedalumina, sulfated silica-coated alumina, or any combination thereof.

Embodiment 51

The composition defined in any one of embodiments 30-44, wherein theactivator comprises a fluorided solid oxide and/or a sulfated solidoxide.

Embodiment 52

The composition defined in any one of embodiments 48-51, wherein theactivator further comprises any metal or metal ion disclosed herein,e.g., zinc, nickel, vanadium, titanium, silver, copper, gallium, tin,tungsten, molybdenum, zirconium, or any combination thereof.

Embodiment 53

The composition defined in any one of embodiments 30-52, wherein thecatalyst composition comprises a co-catalyst, e.g., any co-catalystdisclosed herein.

Embodiment 54

The composition defined in any one of embodiments 30-53, wherein theco-catalyst comprises any organoaluminum compound disclosed herein.

Embodiment 55

The composition defined in embodiment 54, wherein the organoaluminumcompound comprises trimethylaluminum, triethylaluminum,triisobutylaluminum, or a combination thereof.

Embodiment 56

The composition defined in any one of embodiments 48-55, wherein thecatalyst composition comprises catalyst component I, catalyst componentII, a solid oxide treated with an electron-withdrawing anion, and anorganoaluminum compound.

Embodiment 57

The composition defined in any one of embodiments 48-56, wherein thecatalyst composition is substantially free of aluminoxane compounds,organoboron or organoborate compounds, ionizing ionic compounds, orcombinations thereof.

Embodiment 58

The composition defined in any one of embodiments 30-57, wherein aweight ratio of catalyst component I to catalyst component II in thecatalyst composition is in any range disclosed herein, e.g., from about10:1 to about 1:10, from about 5:1 to about 1:5, from about 2:1 to about1:2, etc.

Embodiment 59

The composition defined in any one of embodiments 30-58, wherein thecatalyst composition is produced by a process comprising contacting, inany order, catalyst component I, catalyst component II, and theactivator.

Embodiment 60

The composition defined in any one of embodiments 30-58, wherein thecatalyst composition is produced by a process comprising contacting, inany order, catalyst component I, catalyst component II, the activator,and the co-catalyst.

Embodiment 61

The composition defined in any one of embodiments 30-60, wherein acatalyst activity of the catalyst composition is in any range disclosedherein, e.g., from about 150 to about 10,000, from about 500 to about7,500, from about 1,000 to about 5,000 grams, etc., of ethylene polymerper gram of activator-support per hour, under slurry polymerizationconditions, with a triisobutylaluminum co-catalyst, using isobutane as adiluent, and with a polymerization temperature of 90° C. and a reactorpressure of 390 psig.

Embodiment 62

An olefin polymerization process, the process comprising contacting thecatalyst composition defined in any one of embodiments 30-61 with anolefin monomer and an optional olefin comonomer in a polymerizationreactor system under polymerization conditions to produce an olefinpolymer.

Embodiment 63

The process defined in embodiment 62, wherein the olefin monomercomprises any olefin monomer disclosed herein, e.g., any C₂-C₂₀ olefin.

Embodiment 64

The process defined in embodiment 62 or 63, wherein the olefin monomerand the optional olefin comonomer independently comprise a C₂-C₂₀alpha-olefin.

Embodiment 65

The process defined in any one of embodiments 62-64, wherein the olefinmonomer comprises ethylene.

Embodiment 66

The process defined in any one of embodiments 62-65, wherein thecatalyst composition is contacted with ethylene and an olefin comonomercomprising a C₃-C₁₀ alpha-olefin.

Embodiment 67

The process defined in any one of embodiments 62-66, wherein thecatalyst composition is contacted with ethylene and an olefin comonomercomprising 1-butene, 1-hexene, 1-octene, or a mixture thereof.

Embodiment 68

The process defined in any one of embodiments 62-64, wherein the olefinmonomer comprises propylene.

Embodiment 69

The process defined in any one of embodiments 62-68, wherein thepolymerization reactor system comprises a batch reactor, a slurryreactor, a gas-phase reactor, a solution reactor, a high pressurereactor, a tubular reactor, an autoclave reactor, or a combinationthereof.

Embodiment 70

The process defined in any one of embodiments 62-69, wherein thepolymerization reactor system comprises a slurry reactor, a gas-phasereactor, a solution reactor, or a combination thereof.

Embodiment 71

The process defined in any one of embodiments 62-70, wherein thepolymerization reactor system comprises a loop slurry reactor.

Embodiment 72

The process defined in any one of embodiments 62-71, wherein thepolymerization reactor system comprises a single reactor.

Embodiment 73

The process defined in any one of embodiments 62-71, wherein thepolymerization reactor system comprises 2 reactors.

Embodiment 74

The process defined in any one of embodiments 62-71, wherein thepolymerization reactor system comprises more than 2 reactors.

Embodiment 75

The process defined in any one of embodiments 62-74, wherein the olefinpolymer comprises any olefin polymer disclosed herein.

Embodiment 76

The process defined in any one of embodiments 62-67 and 69-75, whereinthe olefin polymer is an ethylene homopolymer, an ethylene/1-butenecopolymer, an ethylene/1-hexene copolymer, or an ethylene/1-octenecopolymer.

Embodiment 77

The process defined in any one of embodiments 62-67 and 69-75, whereinthe olefin polymer is an ethylene/1-hexene copolymer.

Embodiment 78

The process defined in any one of embodiments 62-64 and 68-75, whereinthe olefin polymer is a polypropylene homopolymer or a propylene-basedcopolymer.

Embodiment 79

The process defined in any one of embodiments 62-78, wherein thepolymerization conditions comprise a polymerization reaction temperaturein a range from about 60° C. to about 120° C. and a reaction pressure ina range from about 200 to about 1000 psig (about 1.4 to about 6.9 MPa).

Embodiment 80

The process defined in any one of embodiments 62-79, wherein thepolymerization conditions are substantially constant, e.g., for aparticular polymer grade.

Embodiment 81

The process defined in any one of embodiments 62-80, wherein no hydrogenis added to the polymerization reactor system.

Embodiment 82

The process defined in any one of embodiments 62-80, wherein hydrogen isadded to the polymerization reactor system.

Embodiment 83

The process defined in any one of embodiments 62-82, wherein the olefinpolymer produced is defined in any one of embodiments 1-27.

Embodiment 84

An olefin polymer produced by the olefin polymerization process definedin any one of embodiments 62-82.

Embodiment 85

An ethylene polymer defined in any one of embodiments 1-27 produced bythe process defined in any one of embodiments 62-82.

Embodiment 86

An article (e.g., a blow molded article) comprising the polymer definedin any one of embodiments 84-85.

Embodiment 87

A method or forming or preparing an article of manufacture comprising anolefin polymer, the method comprising (i) performing the olefinpolymerization process defined in any one of embodiments 62-82 toproduce an olefin polymer (e.g., the ethylene polymer of any one ofembodiments 1-27), and (ii) forming the article of manufacturecomprising the olefin polymer, e.g., via any technique disclosed herein.

Embodiment 88

The article defined in any one of embodiments 86-87, wherein the articleis an agricultural film, an automobile part, a bottle, a container forchemicals, a drum, a fiber or fabric, a food packaging film orcontainer, a food service article, a fuel tank, a geomembrane, ahousehold container, a liner, a molded product, a medical device ormaterial, an outdoor storage product, outdoor play equipment, a pipe, asheet or tape, a toy, or a traffic barrier.

The invention claimed is:
 1. A polymerization process comprising: contacting a metallocene-based catalyst composition with ethylene and an α-olefin comonomer in the presence of hydrogen in a polymerization reactor system under polymerization conditions to produce an ethylene/α-olefin copolymer; wherein: a weight percentage of the α-olefin comonomer based on ethylene is in a range from about 0.01 wt. % to about 0.38 wt. %; a ppm by weight of hydrogen based on ethylene is in a range from about 5 ppm to about 1000 ppm; and the ethylene/α-olefin copolymer has a density in a range from about 0.945 to about 0.960 g/cm³ and a high load melt index (HLMI) in a range from about 1 to about 25 g/10 min.
 2. The process of claim 1, wherein the catalyst composition comprises: a first metallocene compound comprising an unbridged zirconium or hafnium based metallocene compound containing two cyclopentadienyl groups, two indenyl groups, or a cyclopentadienyl group and an indenyl group; a second metallocene compound comprising a bridged zirconium or hafnium based metallocene compound with a cyclopentadienyl group and a fluorenyl group; an activator-support comprising a fluorided solid oxide, a sulfated solid oxide, a phosphated solid oxide, or a combination thereof; and an organoaluminum co-catalyst.
 3. The process of claim 2, wherein the bridged zirconium or hafnium based metallocene compound has a cyclopentadienyl group with an alkenyl substituent, and a fluorenyl group.
 4. The process of claim 2, wherein the bridged zirconium or hafnium based metallocene compound has an aryl group substituent on the bridging group.
 5. The process of claim 2, wherein the unbridged zirconium or hafnium based metallocene compound has a cyclopentadienyl group and an indenyl group.
 6. The process of claim 2, wherein the activator-support comprises fluorided alumina, sulfated alumina, fluorided silica-alumina, sulfated silica-alumina, fluorided silica-coated alumina, sulfated silica-coated alumina, or any combination thereof.
 7. The process of claim 2, wherein the organoaluminum co-catalyst comprises trimethylaluminum, triethylaluminum, triisobutylaluminum, or a combination thereof.
 8. The process of claim 2, wherein a weight ratio of the first metallocene compound to the second metallocene compound is in a range from about 2:1 to about 1:2.
 9. The process of claim 1, wherein the polymerization reactor system comprises a slurry reactor, a gas-phase reactor, a solution reactor, or a combination thereof.
 10. The process of claim 1, wherein the polymerization reactor system comprises a loop slurry reactor.
 11. The process of claim 1, wherein the polymerization reactor system comprises two reactors.
 12. The process of claim 1, wherein the polymerization reactor system comprises one reactor.
 13. The process of claim 12, wherein the catalyst composition comprises two metallocene compounds, an activator, and a co-catalyst.
 14. The process of claim 12, wherein the ppm by weight of hydrogen based on ethylene is in a range from about 25 ppm to about 750 ppm.
 15. The process of claim 12, wherein the α-olefin comonomer comprises 1-butene, 1-hexene, 1-octene, or a combination thereof.
 16. The process of claim 15, wherein the weight percentage of the α-olefin comonomer based on ethylene is in a range from about 0.18 wt. % to about 0.38 wt. %.
 17. The process of claim 15, wherein the ppm by weight of hydrogen based on ethylene is in a range from about 30 ppm to about 53 ppm.
 18. The process of claim 15, wherein the weight percentage of hydrogen based on the α-olefin comonomer is in a range from about 0.8 wt. % to about 3 wt. %.
 19. The process of claim 1, wherein: the catalyst composition comprises two metallocene compounds, an activator, and a co-catalyst; the polymerization reactor system comprises a single loop slurry reactor; and the α-olefin comonomer comprises a C₃-C₁₀ α-olefin.
 20. The process of claim 19, wherein: the weight percentage of the α-olefin comonomer based on ethylene is in a range from about 0.18 wt. % to about 0.38 wt. %; the ppm by weight of hydrogen based on ethylene is in a range from about 30 ppm to about 53 ppm; and the ethylene/α-olefin copolymer comprises an ethylene/1-butene copolymer, an ethylene/1-hexene copolymer, or an ethylene/1-octene copolymer. 